{"as_of":"2026-08-16T17:34:00Z","caps":{"database_statements":6,"inbound":100,"outbound":100},"context_digest":"sha256:f0ecdce7ea48c976c8fa2931d99cdbf0203172c71f03cf503b5710e80422eda9","coverage":[{"denominator":80,"lane":"reference_resolution","note":"Typed states for the displayed outbound observations.","records_observed":80,"source":"paper_references, paper_reference_links","source_observed_at":"2026-08-14T14:41:17.393619Z","state":"measured"},{"denominator":81,"lane":"standing_notices","note":"One-hop event checks from named stored sources.","records_observed":81,"source":"scholarly_work_events, retraction_status_cache","source_observed_at":"2026-08-16T06:30:59.297886+00:00","state":"measured"},{"denominator":1,"lane":"inbound_itemization","note":"Pith citing papers itemized under the disclosed page cap.","records_observed":1,"source":"paper_references, paper_reference_links","source_observed_at":"2026-05-17T03:17:30.863114Z","state":"measured"},{"denominator":1,"lane":"external_citation_measurements","note":"A source-named dated measurement, never combined with another source.","records_observed":0,"source":"arxiv_reference","source_observed_at":"2026-05-17T03:18:56.755485Z","state":"measured"}],"external_citation_measurements":[],"inbound":[{"citation":{"cited_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"cited_work":{"arxiv_id":"1908.02921","doi":null,"metadata_source":"arxiv_reference","pith_arxiv_id":"1908.02921","snapshot_observed_at":"2026-06-05T21:23:00.469572Z","title":"Siino, [arXiv:1908.02921 [gr-qc]]","venue":null,"work_id":"c98606a1-028c-4376-b6f6-0bf1d40f3496","year":1908},"citing_paper":{"arxiv_id":"2512.01688","last_updated":"2026-05-05T12:07:51Z","snapshot_observed_at":"2026-08-15T04:15:12.671483Z","submitted_at":"2025-12-01T13:56:04Z","title":"Gravitational lensing inside and outside of a marginally unstable photon sphere in a general, static, spherically symmetric, and asymptotically-flat spacetime in strong deflection limits","version":3},"reference_index":53,"source":"pdf_text","source_observed_at":"2026-05-17T03:17:30.863114Z"},"links":{"cited_paper":"/paper/1908.02921","citing_paper":"/paper/2512.01688"},"observation_digest":"sha256:9ce835f2da93f8841124f846e81b1ebcd5e3af670e173178b3fb38fb1d84ce52","observation_id":"b0f5ac3e-7caf-4c8d-b2b5-74076f2f0cf7","resolution":{"observed_at":"2026-05-17T03:18:56.758097Z","resolver_source":"arxiv_id","status":"verified_exact"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}}],"links":{"evidence":"/evidence","html":"/paper/1908.02921/citation-record","integrity":"/paper/1908.02921/integrity","json":"/paper/1908.02921/citation-record.json","paper":"/paper/1908.02921"},"outbound":[{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.866773Z","title":"Firstly, we want to distinguish the effect of Ricci curvature Rabkakb from the deviation equation given in the previous section (Eq","venue":null,"work_id":"6007d656-33de-46d1-87e0-3efa15538a27","year":null},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":1,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.000230Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:89f278d54ade630cd2a612723ea768b800a69291ea2c3164fd3424a4a31a4572","observation_id":"9ccf4f29-44d0-4621-afc3-6d80a5a542f4","resolution":{"observed_at":"2026-08-14T14:41:18.871724Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":null,"pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.007767Z","title":null,"venue":null,"work_id":null,"year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":2,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.007767Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:cf0bcb04fdf4cf88d6a67133eedad5ad42c0cbe597a872d8cef0c040ec69198b","observation_id":"bc715cb6-3b9a-4d59-94cd-5f83cb57b722","resolution":{"observed_at":"2026-08-14T14:41:17.007767Z","resolver_source":null,"status":"unresolved"},"standing_notice":{"events":[],"reason":"canonical_work_link_unavailable","source_receipts":[],"state":"unavailable"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.739470Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"9ddfe83b-0338-4b38-86eb-3d091be19f8f","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":3,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.013830Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:a172b174236b949ac203ad749e65fff75ae171087233110adf56b8477cbe375a","observation_id":"28c3b5d9-aa41-4607-aef0-5e3e5ee8dee1","resolution":{"observed_at":"2026-08-14T14:41:18.744051Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.723468Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"ecf4fabf-8c78-4ceb-91ce-3dfcdd1902c1","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":4,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.019233Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6d6fe5cb6495c04dc40de9166a010e49fd1934c25c1048d5ebb81f3adf57e6ea","observation_id":"11b5246a-09bc-430e-86a7-434f721f858a","resolution":{"observed_at":"2026-08-14T14:41:18.728655Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.707305Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"fda8a8ca-6b80-422f-930e-f3436fe2078d","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":5,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.024827Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:1a4a71fc6cc09b5a7508a709114c778911a891eff4334043e6999fa47e384de4","observation_id":"b40dac34-a1b5-49b8-87e5-1ad66dcb3905","resolution":{"observed_at":"2026-08-14T14:41:18.712409Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.689513Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"88fde6d0-391f-475e-b753-3d5352899e54","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":6,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.030210Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:72f0f2cac6966e8ce82cbb359d9905342a277ba3cc7579886958b8fbee8b456c","observation_id":"b3f77163-d7fd-4b5a-aca2-aa343c282ac4","resolution":{"observed_at":"2026-08-14T14:41:18.695692Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.672191Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"1da8f84f-e208-4d68-ac31-83f1779a64eb","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":7,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.035549Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:a1cc3180d791ca278eb14defbaec7497587c4a2cfe0ac28e32fa7e63117504ba","observation_id":"2141648a-3a86-4283-a1ab-b7998c206d57","resolution":{"observed_at":"2026-08-14T14:41:18.677635Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.654597Z","title":"First M87 Event Horizon Telescope Results","venue":null,"work_id":"04eaa8dc-3f77-46e8-8eca-f78403672b3d","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":8,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.041725Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:b3634865133a5d6cc4e793d44ea3d7cfcada04374cfbfe28c1aa6d92f96ce572","observation_id":"562d71cb-d5b1-4bb0-ab3f-5e3fc52879f3","resolution":{"observed_at":"2026-08-14T14:41:18.660547Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.637175Z","title":"Topology of event horizon","venue":null,"work_id":"19c20f9f-d3c6-49f9-8d29-aa92d027ed93","year":1998},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":9,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.046490Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:84411b971fc56ac48ec0e59632c12752361afd55b117c4a5037d2189de7986ef","observation_id":"b5f7623c-3412-4b92-abbb-7e40c7eb02b3","resolution":{"observed_at":"2026-08-14T14:41:18.643166Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.620701Z","title":"Topological appearance of event horizon: What is the topology of the event horizon that we can see? Prog","venue":null,"work_id":"bd92dc0e-dcef-463c-a216-0ae59d887c09","year":1998},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":10,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.051496Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:9bdd2f4a356d3f4f36e7d767a99166f6e05923cc91e36474fc3dbc4725d1c482","observation_id":"b764b13e-b591-42b8-966d-ce6ffd615a51","resolution":{"observed_at":"2026-08-14T14:41:18.626500Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.604435Z","title":"The Asymmetric merger of black holes","venue":null,"work_id":"b02196d1-bd60-48a6-9004-1ed1f56d11bc","year":1999},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":11,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.056481Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:e1bd9ab2954c5d33a6f9615171b42f90144e533d7e825e6ed19ab8b55035b543","observation_id":"b259c3ba-e070-432d-a184-a2d36bcb4ca3","resolution":{"observed_at":"2026-08-14T14:41:18.609574Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.589553Z","title":"Cohen, Jeffrey D","venue":null,"work_id":"36893b1d-a081-4d97-a813-7bf490e50014","year":2012},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":12,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.061466Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:08e89aa05cd45f019f24313c4bc8b5218bb0013be8e612a6808ff6929cfe8072","observation_id":"bd98be69-dd55-44f2-a184-19c32c767618","resolution":{"observed_at":"2026-08-14T14:41:18.594005Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.573747Z","title":"Kidder, and Saul A","venue":null,"work_id":"6f13d9e6-d175-4fdf-9f3e-ed096b6b10ee","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":13,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.066770Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:3ea7d2a4fec62070f30004237a4574c7364ed53295d0601a696f2fcadd51c2b0","observation_id":"e48f87ee-2592-41c6-ae84-925923bf248d","resolution":{"observed_at":"2026-08-14T14:41:18.578694Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.556983Z","title":"Black hole fusion in the extreme mass ratio limit","venue":null,"work_id":"f172d3f1-e5a9-47b5-855a-57ba6552bd3e","year":2018},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":14,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.071532Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:03a2a6d0951ff9d3a0f6da1151fa3256c4a7aec75567a2324b95cccf171de826","observation_id":"c4cad5a1-d5ff-412d-8dbd-27a4ebc65864","resolution":{"observed_at":"2026-08-14T14:41:18.562423Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.541811Z","title":null,"venue":null,"work_id":"ab2f7ad1-aac4-472a-803f-2b1304a05b44","year":2011},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":15,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.075613Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:bd595e71361feafc854bda050aee2a8d8b3d67b7e99a06f0c1e60cf2010f96bd","observation_id":"b2a6a262-f8d8-496b-b9a1-cd00f0f74cf0","resolution":{"observed_at":"2026-08-14T14:41:18.545965Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.526825Z","title":"Viewing the shadow of the black hole at the galactic center","venue":null,"work_id":"b93db133-72a7-44d2-976f-e7c4b7ea2687","year":2000},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":16,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.079787Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6f30bc299aa2e67793c172445b102df541a91d7895a61696044a1ab51b026e19","observation_id":"315dc80e-501e-4cf3-9f28-00a81f0a8347","resolution":{"observed_at":"2026-08-14T14:41:18.531802Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.510274Z","title":"Broderick, Abraham Loeb, and Ramesh Narayan","venue":null,"work_id":"90501105-6825-4cf8-8f37-2398c8be7006","year":2009},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":17,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.083949Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:45fdb60019ed5646218f913b37c66c442f9d23b3816aca331f0290e47c3aae56","observation_id":"1e3954a5-7486-499d-8fa7-07d82d00ed33","resolution":{"observed_at":"2026-08-14T14:41:18.515399Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.493796Z","title":"Broderick, Vincent L","venue":null,"work_id":"bd212e32-2ead-4e53-9a03-cfdfcafeaddc","year":2011},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":18,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.088158Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:0786e8c32f0ae0bb01c0ee536dc4136732f1ca1aba8c8dd038ec09b0fb8bf5ac","observation_id":"435cd8b6-0bb0-4cf8-952c-4cbe80d302f6","resolution":{"observed_at":"2026-08-14T14:41:18.499694Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.477765Z","title":"Shape and position of the shadow in the δ = 2 Tomimatsu-Sato space-time","venue":null,"work_id":"aadc3030-b51e-41b3-9b25-2500924b8e5d","year":2010},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":19,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.092685Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:d7859ccf6a3cbe2bb5a3662a33809c9c6f408375cb8d95a598bcbe0dfada4de9","observation_id":"b530221f-4918-493e-9717-14e44785c53b","resolution":{"observed_at":"2026-08-14T14:41:18.482925Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.462005Z","title":"Testing the rotational nature of the supermassive object m87 from the circularity and size of its first image","venue":null,"work_id":"49e5ef6d-176a-4294-b19d-e830f3abcfa2","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":20,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.097130Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:31eb8539799b64733ed72e814b7a9f256f235c43f8db1ed608f0f7c17baf162c","observation_id":"b8b2c1f8-69e6-430f-99fb-8a5b350be495","resolution":{"observed_at":"2026-08-14T14:41:18.466625Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.446158Z","title":"Shadows of colliding black holes","venue":null,"work_id":"ab3c85e2-241e-4283-9d59-fa79eaf723df","year":2011},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":21,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.101720Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:18afb2db5d6717aacee3319d0589549c6aebf3cc6a86c285bdde5a0820fce1fa","observation_id":"798ef382-ceba-40bb-8f8f-81c6b898f373","resolution":{"observed_at":"2026-08-14T14:41:18.451204Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.429019Z","title":"Shadows of Multi-Black Holes: Analytic Exploration","venue":null,"work_id":"e16dfdf2-1bd0-417c-92ca-7e9918227ef1","year":2012},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":22,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.106197Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:5ef69557f23beb4472f8334d10fdbc698ea21dbaa23bafa685aa4a8450926dc5","observation_id":"5e432c43-5c49-482b-8308-bdf4cd5a2a28","resolution":{"observed_at":"2026-08-14T14:41:18.434047Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.413377Z","title":"Shadow of Kerr-Taub-NUT black hole","venue":null,"work_id":"2deb7808-c9ce-4f6d-a6e4-7c376176dbe6","year":2013},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":23,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.111228Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:a427ce8744455a4a5052efc79d489ccff34eee1f381362935f8160f50c0c49e3","observation_id":"566aa7e5-17c1-4fb5-9674-753b75927778","resolution":{"observed_at":"2026-08-14T14:41:18.418388Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.397925Z","title":"Photon Regions and Shadows of Kerr-Newman-NUT Black Holes with a Cosmological Constant","venue":null,"work_id":"925bafe0-c6b9-4e3c-94b5-d35e246349cc","year":2014},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":24,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.116309Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:fa571b0d453bee2f6c3958f1835a63a61fafef6d308eec6ddb35bfb9681271ef","observation_id":"4a476937-c3c2-4de8-ae71-1f96b9b06b66","resolution":{"observed_at":"2026-08-14T14:41:18.402236Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.381791Z","title":"Eiroa, and Gaston Giribet","venue":null,"work_id":"68ba6fec-2e27-4b36-8bd6-c7ce8a151e97","year":2010},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":25,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.121207Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6c7b4693303b54dfaee232f919b9701ea365d7ab3692f27141db2eaa4d656bbf","observation_id":"74c3727e-3cd7-42c2-b084-7ee105e7a191","resolution":{"observed_at":"2026-08-14T14:41:18.387767Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.365861Z","title":null,"venue":null,"work_id":"08abe279-859a-4f47-9498-be1766027f51","year":2012},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":26,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.126329Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:4af9842087a2cb93ca1b0c930de8bcb5ea8f1c126e87b9f326b64b606957dca4","observation_id":"888c089c-f5c9-41f5-9eb7-04ad2201ae24","resolution":{"observed_at":"2026-08-14T14:41:18.370697Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.349842Z","title":"Shadow of a Charged Rotating Black Hole in f (R) Gravity","venue":null,"work_id":"8585029b-3782-45b1-a5f9-9dbf3b28c02a","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":27,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.131171Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:66147e7cad98f0ebcdf5919cb20eb9b8f4a73ce8ad2cf5ee22eddf6fb9976e0c","observation_id":"a953a657-a4b0-4744-80be-877f2fce365c","resolution":{"observed_at":"2026-08-14T14:41:18.354919Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.332193Z","title":null,"venue":null,"work_id":"9c557aa2-84f9-40d4-93c0-e260a8f220b1","year":2017},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":28,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.136103Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:57a71ac051e579b985e9eabdfd7309ebe8f24a3bfe74e47221ed31b0a01cbe6b","observation_id":"d304f46f-2b9d-4545-b31d-fe182f00bb16","resolution":{"observed_at":"2026-08-14T14:41:18.338571Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.316101Z","title":"Hunting for extra dimensions in the shadow of m87","venue":null,"work_id":"757a4419-6dc6-439e-aab6-b4c7995a122b","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":29,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.141251Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:7eac630fdfc2c8d3d6e0554cc0aa63751be6fce809c89fd20d67170b1c2a6874","observation_id":"ebd20027-486c-4d85-a257-eff666cfff3e","resolution":{"observed_at":"2026-08-14T14:41:18.321112Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.299513Z","title":null,"venue":null,"work_id":"662c44e4-d4c0-4366-8e9f-cf25350a21c4","year":2004},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":30,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.146545Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6c83b518689b789b0a891a4b4277be2416a106ce2aaa2d1916b7a9ababc924f4","observation_id":"7c02650b-f84e-4449-b74e-10ebeaf4a69c","resolution":{"observed_at":"2026-08-14T14:41:18.304960Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.283189Z","title":"Upper bound on the radii of black-hole photonspheres","venue":null,"work_id":"f0e74db4-51b5-444c-8533-6a58e250ed66","year":2013},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":31,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.151661Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:f4744f6dc9e462c73993ee4277c5c3734fb4bc4966971a071bb9102688c00a12","observation_id":"88d96bd2-db86-487e-ba19-0835eb669677","resolution":{"observed_at":"2026-08-14T14:41:18.288401Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.267041Z","title":"On the number of light rings in curved spacetimes of ultra-compact objects","venue":null,"work_id":"922c75e2-e42d-4e7f-9237-6b97225f0c5a","year":2018},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":32,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.157000Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:8daaa7fdfbff4606e1b3e2f3dea813f3d0a44910b83f1d80dbe5d6c8d321aa7d","observation_id":"7ea4fd2b-6581-48c7-b5d8-3ecfee872ffb","resolution":{"observed_at":"2026-08-14T14:41:18.272316Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.250243Z","title":"Absorption and emission spectra of a schwarzschild black hole","venue":null,"work_id":"39e7c19d-2e61-4735-a06f-b80f560664ed","year":1978},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":33,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.161945Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:447d0bf70b9e51b8d8c8cc06120d76dc070b3fe00541af879c54fa6f6d2a6d57","observation_id":"173cf5ea-7911-45d1-b736-e5d2d6c40697","resolution":{"observed_at":"2026-08-14T14:41:18.255759Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.234953Z","title":"Unstable circular null geodesics of static spherically symmetric black holes, regge poles, and quasinormal frequencies","venue":null,"work_id":"919fd575-dc84-4c87-9b5d-3b1511281c22","year":2010},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":34,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.167050Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:2280006716298aa5e531bf6c2e3d4c3c28f760ac749f288a6093c4e2c4cb10d3","observation_id":"f1c91489-116d-4ead-949b-669856d5d38c","resolution":{"observed_at":"2026-08-14T14:41:18.239451Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.220181Z","title":null,"venue":null,"work_id":"723bc033-db06-4b57-aec4-21228f6f8eb5","year":2000},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":35,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.171963Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:e528f9ed54494c41b1c64adef767f0c5cf14ee204fe1336330bef7918307b4fd","observation_id":"9232b6d9-b6a9-48b7-bf13-3a9b10abf4c3","resolution":{"observed_at":"2026-08-14T14:41:18.224425Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.203688Z","title":"Spherical photon orbits around a kerr black hole","venue":null,"work_id":"ab4fb060-0c97-4082-b70b-60445ba9390f","year":1909},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":36,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.176896Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:096117c5778972c33400ce92752e506edc755a084b9bd51517af9e9908447959","observation_id":"fddc21da-a05f-4deb-b55f-bba0aa3d4f70","resolution":{"observed_at":"2026-08-14T14:41:18.209050Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.187669Z","title":null,"venue":null,"work_id":"6591bdcc-ae31-4f53-9906-a84afe2c43b1","year":2001},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":37,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.182399Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:9a96f28d036553431f14335c758e53fcf70efa3f913624bf2f928dc8051d6354","observation_id":"7c81c516-1ae4-44dd-8b3f-2c62102c2e8d","resolution":{"observed_at":"2026-08-14T14:41:18.192590Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.170979Z","title":"Catastrophe theory and its applications","venue":null,"work_id":"5a26ef8e-1175-4857-9ace-b4e2dc175d3e","year":2014},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":38,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.187598Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:d6ec726f9d5ad900e8eaff7b962d04454bb82e32ad1d5bfb38d38e5ac2d991cb","observation_id":"8d131542-cf64-4170-b97c-18e778996d4e","resolution":{"observed_at":"2026-08-14T14:41:18.176313Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.154022Z","title":"The shadow of a collapsing dark star","venue":null,"work_id":"71547f7f-5e6a-4048-b6e1-5a6cf64631b2","year":2018},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":39,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.192517Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:4033dd4245423f2deebca9e089edcf893f5b56765924d0b369c5256083103094","observation_id":"9842f0d4-3621-4911-a379-bd474ea7c25e","resolution":{"observed_at":"2026-08-14T14:41:18.159651Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.137622Z","title":"Quasi-local photon surfaces in general spherically symmetric spacetimes","venue":null,"work_id":"89c18f21-e0e8-453d-8e6c-6b0ac5c0360a","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":40,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.197354Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:4840163c9ccd02cbbe02d756767c5dd25c6592de50aa82dae9be4f851fd1cab2","observation_id":"4fedfb27-91f7-43de-8541-c943c7e31e53","resolution":{"observed_at":"2026-08-14T14:41:18.143029Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.121369Z","title":"Understanding photon sphere and black hole shadow in dynamically evolving spacetimes","venue":null,"work_id":"f2be3bce-7806-410f-bb75-d8ddeab57e89","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":41,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.202171Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:2d9cd6395fbcf6ea535e1150dda93c1d850e06a3ae96eee2f5e4d56728835b76","observation_id":"52e56186-4db5-4dc1-b276-b4f2f347f19c","resolution":{"observed_at":"2026-08-14T14:41:18.126796Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.105181Z","title":"Bisnovatyi-Kogan and Oleg Yu","venue":null,"work_id":"9a5fd8dd-d2cd-4cea-84e6-3051047e4dee","year":2018},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":42,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.211005Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:e4f511a9461c5b5698b63e67b1899ef509d0927eb373b54faca1b32ec163a7b8","observation_id":"c04e026f-71fe-46ea-9a7f-7361b6615fea","resolution":{"observed_at":"2026-08-14T14:41:18.110493Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.089665Z","title":"Transversely trapping surfaces: Dynamical version","venue":null,"work_id":"3edfa665-7666-4355-947f-1783c9c4747f","year":2020},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":43,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.218013Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:7890341b226c6aed6bf82f4c49a6dfe6243c46139e5aa4beb022fe3bd72eae0b","observation_id":"cbc56187-a470-4a0f-bfff-8e133d004b0e","resolution":{"observed_at":"2026-08-14T14:41:18.094651Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.073373Z","title":"The fingerprints of black holes—shadows and their degeneracies","venue":null,"work_id":"b10b9f45-38d4-4c61-bd40-3929d47434bd","year":2017},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":44,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.222898Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:51b0014e243635a426bac3656cbbf5cd6b65d49f03cd47cbd69dbd434c6c79f0","observation_id":"780f0a4e-4087-48b9-b9f6-9bdccbe487b7","resolution":{"observed_at":"2026-08-14T14:41:18.078440Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.058622Z","title":null,"venue":null,"work_id":"a38929bc-2477-4358-8774-667cab167020","year":1984},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":45,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.227760Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:5c6b4f93e28b7b010a645fc6378701ae4043542e2013334001f6918873a8eb9c","observation_id":"ef4d18ee-ae44-4c34-b46d-09002fcf2ab9","resolution":{"observed_at":"2026-08-14T14:41:18.063130Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.042888Z","title":"Spherical steady accretion flows: Dependence on the cosmological constant, exact isothermal solutions, and applications to cosmology","venue":null,"work_id":"71a01ef2-c030-4caa-b1f4-02c990f0d153","year":2013},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":46,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.232567Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:f58cfef597af025c51ee7ce4f04239b37b28cf76cf3093c0dfeeacdc757a4ba5","observation_id":"d04025fc-99f1-4dff-af36-d6767a1a2c39","resolution":{"observed_at":"2026-08-14T14:41:18.048169Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.025803Z","title":"Radial accretion flows on static spherically symmetric black holes.Classical and Quantum Gravity, 32(15):155006, jul 2015","venue":null,"work_id":"b307cfa8-32ce-44b2-9766-4f2cc866f1a8","year":2015},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":47,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.237170Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:ee1d4cd3abe979b9c30fc4a6bb14a4f7daebbc32315a4d65355218a3fb2ae119","observation_id":"7f2b134e-59b3-468a-bb18-10a55b72beaa","resolution":{"observed_at":"2026-08-14T14:41:18.031134Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:18.009250Z","title":"Cveti ˇc, G","venue":null,"work_id":"3366b72f-13e1-41e2-a269-3cd81852dfe0","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":48,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.241401Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:cc4946f337211e144cf7f5caa6cc0533b43d033e76cf7bac940a786918b487c2","observation_id":"12be2d00-556a-460e-8d47-60571996bb93","resolution":{"observed_at":"2026-08-14T14:41:18.014721Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.992041Z","title":"Correspondence between sonic points of ideal photon gas accretion and photon spheres","venue":null,"work_id":"bea73bc8-f79b-4246-ada0-ef560302fef0","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":49,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.245906Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:92910f79ff19e130b58d0c9a088e0ed657984d60d40e91fd2de5c320235bfaef","observation_id":"67e4b438-9c0c-45d3-b731-de7aadecdb94","resolution":{"observed_at":"2026-08-14T14:41:17.997640Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.974883Z","title":"Rotating accretion flows in d dimensions: Sonic points, critical points, and photon spheres","venue":null,"work_id":"944698b2-636a-49a1-9c58-1eb0a6495e92","year":2018},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":50,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.250242Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:8a2b59391d7759e0eb34fad52adbaa08d87de4f782334f0de31a3f4cc7b0be3c","observation_id":"31d1d040-a442-49b9-b229-1b4931896cd4","resolution":{"observed_at":"2026-08-14T14:41:17.980946Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.958568Z","title":"Photon surfaces in spherically, planar, and hyperbolically symmetric spacetimes in d dimensions: Sonic point/photon sphere correspondence","venue":null,"work_id":"d8d59e03-cd85-498b-81b4-93d72c7719eb","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":51,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.254605Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:1642c7044a5213eb39ece875ebcb69d34bbbe8679f56cb27260ae8c12786a0c9","observation_id":"44fe2ec0-c0f5-4cc7-8042-9138615cd009","resolution":{"observed_at":"2026-08-14T14:41:17.964059Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.943366Z","title":"Gibbons and C.M","venue":null,"work_id":"1affea3d-1609-4ed7-bbc9-403850f04445","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":52,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.258932Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:cdb6751ad17497b4c4c0289bba4da204b3274ba8238448a1ca3e17703a8e26a1","observation_id":"522e7f6b-bc6c-449a-9c9a-ef93a5c0c0b1","resolution":{"observed_at":"2026-08-14T14:41:17.947802Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.928076Z","title":null,"venue":null,"work_id":"5bc4b787-e3bf-44b9-ab4e-0b0a02952441","year":2017},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":53,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.263471Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:b9915b55a8d78be141b0cb05a2fe9de2875ccae36acce124c54237caaebdef91","observation_id":"76787d54-f5ce-404a-a6f4-1c7d87987632","resolution":{"observed_at":"2026-08-14T14:41:17.932431Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.912407Z","title":null,"venue":null,"work_id":"58615840-22aa-4d88-9570-47d861441ee2","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":54,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.268371Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:d7a114430a1d9332f1d2020592e397b546ee82aadc00fbe1010c25ef3ae7c37f","observation_id":"a5f77fcd-8940-4a01-9444-f6d290f5cea9","resolution":{"observed_at":"2026-08-14T14:41:17.918004Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.896535Z","title":null,"venue":null,"work_id":"5425418a-5f7a-4335-81d0-1b54a073ea04","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":55,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.273266Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:5edc875aa6b63458493ea8a962a47240e51cd456176d7e1cd8d71076ee7a88bf","observation_id":"0fa83f23-0ecb-4a15-a739-fe32d99fd195","resolution":{"observed_at":"2026-08-14T14:41:17.901617Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.880466Z","title":"Stability of null orbits on photon spheres and photon surfaces","venue":null,"work_id":"d84ba9cb-0a92-49b8-ab52-f7a70e336da4","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":56,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.278314Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6a242b36c5d2c514f219766652d6064a7a502662b7f6c2558712e3055dce1b21","observation_id":"be39b0e9-f59f-435a-a56c-1086e7d1f29c","resolution":{"observed_at":"2026-08-14T14:41:17.885765Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.863991Z","title":"Spinors and space-time, vol","venue":null,"work_id":"1adf862b-777b-4d24-9e83-8646797f6234","year":1984},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":57,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.283195Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:df8d10adfe366359248db9b7533c8f89c159a9b2cfba8319ed80066b35e427f4","observation_id":"8ac244c4-2d5b-4c74-a0ea-c2cad96c4ead","resolution":{"observed_at":"2026-08-14T14:41:17.869577Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.848312Z","title":"Geroch, E","venue":null,"work_id":"1f01c7ca-8c78-4350-94bd-17a717ebb847","year":1972},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":58,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.288011Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:a1db5d9a03c55571d978afd3bb0ec16cd2ad8a8972f402cd29934e21a5c1d4db","observation_id":"955af573-7e7e-4f37-b32d-eec9d4e0ff75","resolution":{"observed_at":"2026-08-14T14:41:17.853204Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.831773Z","title":null,"venue":null,"work_id":"cb929217-5bfc-4d95-a8e5-8c3637c9324b","year":null},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":59,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.292886Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:34c48c04170f41bba3be166c00f917a6f271e84da5d82078379d347e95b06d2d","observation_id":"e1eb29ef-e313-4023-a884-93094a983330","resolution":{"observed_at":"2026-08-14T14:41:17.837110Z","resolver_source":"raw_fallback","status":"parse_uncertain"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.815818Z","title":null,"venue":null,"work_id":"0ad48d02-d406-4319-9e55-ffbff0e3d15c","year":1981},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":60,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.297979Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:e6329a8f4828d88e214a3dd6d8d98e7e204f2400e364c68873f618fe6aa3af68","observation_id":"2d9e0798-a2a9-425a-9f25-3b30ec314fb0","resolution":{"observed_at":"2026-08-14T14:41:17.820292Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.801752Z","title":null,"venue":null,"work_id":"d4ca46fe-d4f5-45a5-bcf9-f238598c63c9","year":1939},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":61,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.303065Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:919d782415015e65c96cb3b2df791f7f70038bffcfd5441127ca349cb1bf8056","observation_id":"37a50471-6a08-4aa9-b25c-cba78d91d27a","resolution":{"observed_at":"2026-08-14T14:41:17.805941Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.785959Z","title":"Slowly decaying waves on spherically symmetric spacetimes and ultracompact neutron stars","venue":null,"work_id":"f718a868-4489-4621-8ff2-ffbfd2b6663b","year":2016},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":62,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.307955Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:1354d84851ce83249abd904711fe328e9675764b58fbf811918d84f81df7e5a1","observation_id":"20968cb8-43ef-4c97-93c2-97af935d3546","resolution":{"observed_at":"2026-08-14T14:41:17.791009Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.770247Z","title":null,"venue":null,"work_id":"11b8ce4a-19a5-444c-b073-5f44b97b9350","year":2014},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":63,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.312816Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:588d29a15ffd2ccccdbbf55e597f4dc4e1ff719399a14e95e4299e055551c4d1","observation_id":"6466c3db-a6f0-4b84-9ce0-07f00328a979","resolution":{"observed_at":"2026-08-14T14:41:17.775233Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.754724Z","title":null,"venue":null,"work_id":"afb0ebc2-659a-4dc0-a75a-5b302893f509","year":2017},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":64,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.317600Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:3a0c0e521914f64eecb29d9dc2442b0db171f097aa9934d213f216f956fc5a81","observation_id":"80b762c3-3a44-44ff-a297-010dc58e8a1d","resolution":{"observed_at":"2026-08-14T14:41:17.759674Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.738441Z","title":null,"venue":null,"work_id":"710df0a5-7c48-4463-957d-01a020ff1fa2","year":1937},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":65,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.322409Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:b1ed24dffeabab270148344ca8cd30e7640911079df320690c48a59c01aee7ec","observation_id":"398cf8c4-a657-458a-a4a0-deee402d4c90","resolution":{"observed_at":"2026-08-14T14:41:17.743612Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.722946Z","title":null,"venue":null,"work_id":"babea458-dba7-4f75-9cbb-dd28b8e67ef9","year":2002},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":66,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.327367Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:c4d558498b632fc99adf24eee19cf835244a6a76a2b9d3a5101fb0aafbf7fea5","observation_id":"fe0a23eb-5e88-40b6-9e08-9d9b0189f862","resolution":{"observed_at":"2026-08-14T14:41:17.727630Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.707156Z","title":"Light curves of light rays passing through a wormhole","venue":null,"work_id":"ae1a6718-87bd-4d3f-b044-8a1f3f49a6f3","year":2017},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":67,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.332351Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:1b8baf244ca52a5b0d0f32947aab588b51447296a2f5096f2445758e63922fbf","observation_id":"3c6e1a38-4a53-4427-ad16-842c16ed7c08","resolution":{"observed_at":"2026-08-14T14:41:17.712197Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.690794Z","title":null,"venue":null,"work_id":"f5677d1a-0ea3-4ba2-9e11-9c8570be0c1a","year":2003},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":68,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.336993Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:6a9b2aac89344df1aa388703fa546ae22cef9f4d3b5f705dad4d4841f6ce0c8c","observation_id":"f9ceae9e-66d3-46ff-9cfd-2a1cf518a093","resolution":{"observed_at":"2026-08-14T14:41:17.695773Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.674997Z","title":"Eiroa, Gustavo E","venue":null,"work_id":"70f48388-0b2a-48b7-b7db-e9cc87b3c00e","year":2002},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":69,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.342279Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:bc4bf29c5fac2f3756577d7a8f8fb68b85b9abb3840200093ab8b61a92d3d018","observation_id":"e966a0ff-6582-4365-9558-8c9a58816269","resolution":{"observed_at":"2026-08-14T14:41:17.679589Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.659865Z","title":null,"venue":null,"work_id":"8614c82e-b1a7-4195-a755-7196653c0527","year":2003},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":70,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.346962Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:abf5e4ace6e44b1fa2545c08e50b31101701dae41c1b928aa10c650b37c2689c","observation_id":"4c807d46-ccce-4a08-892b-f17cc722952a","resolution":{"observed_at":"2026-08-14T14:41:17.664398Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.644933Z","title":null,"venue":null,"work_id":"c806ae3a-8486-47b3-b1df-8a12ec2d2fa9","year":2007},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":71,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.351627Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:e30c22f03029fd59a87b9ba31b4fdabdf392056575b0adf578923c9a826043a5","observation_id":"b7efd483-a194-4207-9141-53db2e465c11","resolution":{"observed_at":"2026-08-14T14:41:17.649406Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.628663Z","title":"Analytical approach to strong gravitational lensing from ultra- compact objects","venue":null,"work_id":"464b0fad-57a2-44eb-9ddc-f24c350f0831","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":72,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.356455Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:28d88be2cd07278a0059b0991605af9b4b2a8714dcb1ceb9c952024600bac4ae","observation_id":"a8fd00b8-f12e-4196-aea5-d6c368635b26","resolution":{"observed_at":"2026-08-14T14:41:17.633934Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.612508Z","title":"Stefanov, Stoytcho S","venue":null,"work_id":"a33c9baf-9094-49e5-bb40-014aee56848b","year":2010},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":73,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.361334Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:4646e3788a9570697fb9534beba2a6abff9772fb9e114fac18e456daec7f8434","observation_id":"b6d4377a-ff59-46f4-99a9-f0d82c3a22fb","resolution":{"observed_at":"2026-08-14T14:41:17.617636Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.596234Z","title":"Thorne W.L","venue":null,"work_id":"3d7d13aa-c82b-48a8-9c3e-11e24e0048c9","year":1968},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":74,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.366108Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:1fbaa50c95ad01c06352b55e612461887dfcdf936ed422c4bf8a0c6658782e26","observation_id":"f815ebc7-c8ec-428e-b9ba-cf8e71691174","resolution":{"observed_at":"2026-08-14T14:41:17.601189Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.578235Z","title":null,"venue":null,"work_id":"8420b634-d562-484e-97d5-a56ea8c1d9f4","year":1966},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":75,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.370988Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:df67c64c8999465aa5e3cc401451fce11661ac971672d6601fb95c8a476f3bb6","observation_id":"6ca243e9-0a08-4eca-8cb5-cd5bbb0e145f","resolution":{"observed_at":"2026-08-14T14:41:17.584102Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.559886Z","title":"How does a collapsing star look? Physical Review D, 100(8), oct 2019","venue":null,"work_id":"c7ab5fec-23bd-416b-be27-e8deb08e5e18","year":2019},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":76,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.375924Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:58df867ce96c0f7fa4c4ba12bfefd3ac665c403f5fd1c4f93631826c6d5eb42b","observation_id":"b2ffe03e-4dba-44ce-82e4-ef6ed5d17f24","resolution":{"observed_at":"2026-08-14T14:41:17.565290Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.543174Z","title":"TOPOLOGICAL CLASSIFICATION OF BLACK HOLES: GENERIC MAXWELL SET AND CREASE SET OF a HORIZON","venue":null,"work_id":"c1199b0a-4e1f-4647-8d10-f21b420a7ae7","year":2011},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":77,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.380446Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:b422835e148902aacc3037016bdccfe0233d47c6f850e4115e6a8c6369aea046","observation_id":"ef8084bb-056f-4371-a0f5-e24296f45bb5","resolution":{"observed_at":"2026-08-14T14:41:17.548491Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":"qc/0505004","doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.486569Z","title":"Topology of event horizon in axially symmetric spacetime: Classification of maxwell set with symmetry","venue":null,"work_id":"9c012abf-94c9-4ba0-88a0-62e193c4a0ef","year":2005},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":78,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.384700Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:ad94eeb0f6681761149901e11250c93794e2bad9905c85244667ecbb276ec7c4","observation_id":"9551010b-4871-4ae4-ba9d-ffe4c7273845","resolution":{"observed_at":"2026-08-14T14:41:17.496855Z","resolver_source":"raw_fallback","status":"verified_exact"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.525640Z","title":null,"venue":null,"work_id":"be267b24-208b-4916-be0d-f7855d0838b8","year":1978},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":79,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.389307Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:acd4e8c0c04c48e8501676b66311616195d2f37a89adcfec495d18a06fdfd03d","observation_id":"86117b24-ad24-45b9-ae8c-47eb2967e303","resolution":{"observed_at":"2026-08-14T14:41:17.530701Z","resolver_source":"raw_fallback","status":"unresolved"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}},{"citation":{"cited_paper":null,"cited_work":{"arxiv_id":null,"doi":null,"metadata_source":"raw_reference","pith_arxiv_id":null,"snapshot_observed_at":"2026-08-14T14:41:17.508357Z","title":"Siino and D","venue":null,"work_id":"7bf0380d-93b7-495c-8817-465df026596b","year":2009},"citing_paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows","version":2},"reference_index":80,"source":"pdf_text","source_observed_at":"2026-08-14T14:41:17.393619Z"},"links":{"citing_paper":"/paper/1908.02921"},"observation_digest":"sha256:262711e3dc29649a2f6accea86490f5e4f360bb4c39e1837ed3e5e28ca76af8d","observation_id":"89daf1dd-9f35-4fd2-9bf6-c56621139cf8","resolution":{"observed_at":"2026-08-14T14:41:17.513708Z","resolver_source":"raw_fallback","status":"verified_fuzzy"},"standing_notice":{"events":[],"observation":"No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.","reason":null,"source_receipts":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"state":"measured"}}],"paper":{"arxiv_id":"1908.02921","last_updated":"2020-10-14T04:54:59Z","latest_version":2,"primary_category":"gr-qc","snapshot_observed_at":"2026-08-16T02:27:55.637266Z","submitted_at":"2019-08-08T03:51:32Z","title":"Causal concept for black hole shadows"},"reference_resolution":{"displayed":80,"state_counts":{"malformed_identifier":0,"metadata_mismatch":0,"parse_uncertain":1,"unresolved":22,"verified_exact":1,"verified_fuzzy":56},"total_outbound_references":80},"refusal":"A citation records a reference. It does not transfer a finding from one paper to another.","schema":"pith.paper-citation-record.v1","standing_sources":[{"observed_at":"2026-08-16T06:30:59.297886+00:00","source":"crossref"},{"observed_at":"2026-08-16T06:30:54.164669+00:00","source":"retraction_watch"}],"thesis":"As of 16 August 2026, this Paper Citation Record lists 80 of 80 outbound references and 1 inbound Pith citation observation for arXiv:1908.02921."}