Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-14T14:41:17.393619Z
Paper Citation Record · LEDGER
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.
A citation records a reference. It does not transfer a finding from one paper to another.
Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-14T14:41:17.393619Z
One-hop event checks from named stored sources.
Source: scholarly_work_events, retraction_status_cache, observed 2026-08-15T06:32:42.880941+00:00
Pith citing papers itemized under the disclosed page cap.
Source: paper_references, paper_reference_links, observed 2026-05-17T03:17:30.863114Z
A source-named dated measurement, never combined with another source.
Source: arxiv_reference, observed 2026-05-17T03:18:56.755485Z
80 of 80 outbound references displayed
External citation measurements
No source-named external measurement is stored.
Observation 9ccf4f29-44d0-4621-afc3-6d80a5a542f4 · outbound
Causal concept for black hole shadows Firstly, we want to distinguish the effect of Ricci curvature Rabkakb from the deviation equation given in the previous section (Eq
Reference 1
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation bc715cb6-3b9a-4d59-94cd-5f83cb57b722 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 2
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 28c3b5d9-aa41-4607-aef0-5e3e5ee8dee1 · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 3
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 11b5246a-09bc-430e-86a7-434f721f858a · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 4
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b40dac34-a1b5-49b8-87e5-1ad66dcb3905 · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 5
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b3f77163-d7fd-4b5a-aca2-aa343c282ac4 · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 6
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 2141648a-3a86-4283-a1ab-b7998c206d57 · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 7
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 562d71cb-d5b1-4bb0-ab3f-5e3fc52879f3 · outbound
Causal concept for black hole shadows First M87 Event Horizon Telescope Results
Reference 8
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b5f7623c-3412-4b92-abbb-7e40c7eb02b3 · outbound
Causal concept for black hole shadows Topology of event horizon
Reference 9
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b764b13e-b591-42b8-966d-ce6ffd615a51 · outbound
Causal concept for black hole shadows Topological appearance of event horizon: What is the topology of the event horizon that we can see? Prog
Reference 10
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b259c3ba-e070-432d-a184-a2d36bcb4ca3 · outbound
Causal concept for black hole shadows The Asymmetric merger of black holes
Reference 11
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation bd98be69-dd55-44f2-a184-19c32c767618 · outbound
Causal concept for black hole shadows Cohen, Jeffrey D
Reference 12
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation e48f87ee-2592-41c6-ae84-925923bf248d · outbound
Causal concept for black hole shadows Kidder, and Saul A
Reference 13
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation c4cad5a1-d5ff-412d-8dbd-27a4ebc65864 · outbound
Causal concept for black hole shadows Black hole fusion in the extreme mass ratio limit
Reference 14
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b2a6a262-f8d8-496b-b9a1-cd00f0f74cf0 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 15
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 315dc80e-501e-4cf3-9f28-00a81f0a8347 · outbound
Causal concept for black hole shadows Viewing the shadow of the black hole at the galactic center
Reference 16
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 1e3954a5-7486-499d-8fa7-07d82d00ed33 · outbound
Causal concept for black hole shadows Broderick, Abraham Loeb, and Ramesh Narayan
Reference 17
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 435cd8b6-0bb0-4cf8-952c-4cbe80d302f6 · outbound
Causal concept for black hole shadows Broderick, Vincent L
Reference 18
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b530221f-4918-493e-9717-14e44785c53b · outbound
Causal concept for black hole shadows Shape and position of the shadow in the δ = 2 Tomimatsu-Sato space-time
Reference 19
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b8b2c1f8-69e6-430f-99fb-8a5b350be495 · outbound
Causal concept for black hole shadows Testing the rotational nature of the supermassive object m87 from the circularity and size of its first image
Reference 20
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 798ef382-ceba-40bb-8f8f-81c6b898f373 · outbound
Causal concept for black hole shadows Shadows of colliding black holes
Reference 21
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 5e432c43-5c49-482b-8308-bdf4cd5a2a28 · outbound
Causal concept for black hole shadows Shadows of Multi-Black Holes: Analytic Exploration
Reference 22
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 566aa7e5-17c1-4fb5-9674-753b75927778 · outbound
Causal concept for black hole shadows Shadow of Kerr-Taub-NUT black hole
Reference 23
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 4a476937-c3c2-4de8-ae71-1f96b9b06b66 · outbound
Causal concept for black hole shadows Photon Regions and Shadows of Kerr-Newman-NUT Black Holes with a Cosmological Constant
Reference 24
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 74c3727e-3cd7-42c2-b084-7ee105e7a191 · outbound
Causal concept for black hole shadows Eiroa, and Gaston Giribet
Reference 25
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 888c089c-f5c9-41f5-9eb7-04ad2201ae24 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 26
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation a953a657-a4b0-4744-80be-877f2fce365c · outbound
Causal concept for black hole shadows Shadow of a Charged Rotating Black Hole in f (R) Gravity
Reference 27
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation d304f46f-2b9d-4545-b31d-fe182f00bb16 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 28
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation ebd20027-486c-4d85-a257-eff666cfff3e · outbound
Causal concept for black hole shadows Hunting for extra dimensions in the shadow of m87
Reference 29
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 7c02650b-f84e-4449-b74e-10ebeaf4a69c · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 30
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 88d96bd2-db86-487e-ba19-0835eb669677 · outbound
Causal concept for black hole shadows Upper bound on the radii of black-hole photonspheres
Reference 31
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 7ea4fd2b-6581-48c7-b5d8-3ecfee872ffb · outbound
Causal concept for black hole shadows On the number of light rings in curved spacetimes of ultra-compact objects
Reference 32
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 173cf5ea-7911-45d1-b736-e5d2d6c40697 · outbound
Causal concept for black hole shadows Absorption and emission spectra of a schwarzschild black hole
Reference 33
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation f1c91489-116d-4ead-949b-669856d5d38c · outbound
Causal concept for black hole shadows Unstable circular null geodesics of static spherically symmetric black holes, regge poles, and quasinormal frequencies
Reference 34
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 9232b6d9-b6a9-48b7-bf13-3a9b10abf4c3 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 35
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation fddc21da-a05f-4deb-b55f-bba0aa3d4f70 · outbound
Causal concept for black hole shadows Spherical photon orbits around a kerr black hole
Reference 36
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 7c81c516-1ae4-44dd-8b3f-2c62102c2e8d · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 37
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 8d131542-cf64-4170-b97c-18e778996d4e · outbound
Causal concept for black hole shadows Catastrophe theory and its applications
Reference 38
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 9842f0d4-3621-4911-a379-bd474ea7c25e · outbound
Causal concept for black hole shadows The shadow of a collapsing dark star
Reference 39
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 4fedfb27-91f7-43de-8541-c943c7e31e53 · outbound
Causal concept for black hole shadows Quasi-local photon surfaces in general spherically symmetric spacetimes
Reference 40
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 52e56186-4db5-4dc1-b276-b4f2f347f19c · outbound
Causal concept for black hole shadows Understanding photon sphere and black hole shadow in dynamically evolving spacetimes
Reference 41
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation c04e026f-71fe-46ea-9a7f-7361b6615fea · outbound
Causal concept for black hole shadows Bisnovatyi-Kogan and Oleg Yu
Reference 42
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation cbc56187-a470-4a0f-bfff-8e133d004b0e · outbound
Causal concept for black hole shadows Transversely trapping surfaces: Dynamical version
Reference 43
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 780f0a4e-4087-48b9-b9f6-9bdccbe487b7 · outbound
Causal concept for black hole shadows The fingerprints of black holes—shadows and their degeneracies
Reference 44
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation ef4d18ee-ae44-4c34-b46d-09002fcf2ab9 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 45
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation d04025fc-99f1-4dff-af36-d6767a1a2c39 · outbound
Causal concept for black hole shadows Spherical steady accretion flows: Dependence on the cosmological constant, exact isothermal solutions, and applications to cosmology
Reference 46
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 7f2b134e-59b3-468a-bb18-10a55b72beaa · outbound
Causal concept for black hole shadows Radial accretion flows on static spherically symmetric black holes.Classical and Quantum Gravity, 32(15):155006, jul 2015
Reference 47
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 12be2d00-556a-460e-8d47-60571996bb93 · outbound
Causal concept for black hole shadows Cveti ˇc, G
Reference 48
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 67e4b438-9c0c-45d3-b731-de7aadecdb94 · outbound
Causal concept for black hole shadows Correspondence between sonic points of ideal photon gas accretion and photon spheres
Reference 49
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 31d1d040-a442-49b9-b229-1b4931896cd4 · outbound
Causal concept for black hole shadows Rotating accretion flows in d dimensions: Sonic points, critical points, and photon spheres
Reference 50
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 44fe2ec0-c0f5-4cc7-8042-9138615cd009 · outbound
Causal concept for black hole shadows Photon surfaces in spherically, planar, and hyperbolically symmetric spacetimes in d dimensions: Sonic point/photon sphere correspondence
Reference 51
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 522e7f6b-bc6c-449a-9c9a-ef93a5c0c0b1 · outbound
Causal concept for black hole shadows Gibbons and C.M
Reference 52
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 76787d54-f5ce-404a-a6f4-1c7d87987632 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 53
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation a5f77fcd-8940-4a01-9444-f6d290f5cea9 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 54
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 0fa83f23-0ecb-4a15-a739-fe32d99fd195 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 55
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation be39b0e9-f59f-435a-a56c-1086e7d1f29c · outbound
Causal concept for black hole shadows Stability of null orbits on photon spheres and photon surfaces
Reference 56
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 8ac244c4-2d5b-4c74-a0ea-c2cad96c4ead · outbound
Causal concept for black hole shadows Spinors and space-time, vol
Reference 57
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 955af573-7e7e-4f37-b32d-eec9d4e0ff75 · outbound
Causal concept for black hole shadows Geroch, E
Reference 58
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation e1eb29ef-e313-4023-a884-93094a983330 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 59
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 2d9e0798-a2a9-425a-9f25-3b30ec314fb0 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 60
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 37a50471-6a08-4aa9-b25c-cba78d91d27a · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 61
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 20968cb8-43ef-4c97-93c2-97af935d3546 · outbound
Causal concept for black hole shadows Slowly decaying waves on spherically symmetric spacetimes and ultracompact neutron stars
Reference 62
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 6466c3db-a6f0-4b84-9ce0-07f00328a979 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 63
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 80b762c3-3a44-44ff-a297-010dc58e8a1d · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 64
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 398cf8c4-a657-458a-a4a0-deee402d4c90 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 65
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation fe0a23eb-5e88-40b6-9e08-9d9b0189f862 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 66
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 3c6e1a38-4a53-4427-ad16-842c16ed7c08 · outbound
Causal concept for black hole shadows Light curves of light rays passing through a wormhole
Reference 67
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation f9ceae9e-66d3-46ff-9cfd-2a1cf518a093 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 68
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation e966a0ff-6582-4365-9558-8c9a58816269 · outbound
Causal concept for black hole shadows Eiroa, Gustavo E
Reference 69
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 4c807d46-ccce-4a08-892b-f17cc722952a · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 70
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b7efd483-a194-4207-9141-53db2e465c11 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 71
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation a8fd00b8-f12e-4196-aea5-d6c368635b26 · outbound
Causal concept for black hole shadows Analytical approach to strong gravitational lensing from ultra- compact objects
Reference 72
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b6d4377a-ff59-46f4-99a9-f0d82c3a22fb · outbound
Causal concept for black hole shadows Stefanov, Stoytcho S
Reference 73
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation f815ebc7-c8ec-428e-b9ba-cf8e71691174 · outbound
Causal concept for black hole shadows Thorne W.L
Reference 74
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 6ca243e9-0a08-4eca-8cb5-cd5bbb0e145f · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 75
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b2ffe03e-4dba-44ce-82e4-ef6ed5d17f24 · outbound
Causal concept for black hole shadows How does a collapsing star look? Physical Review D, 100(8), oct 2019
Reference 76
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation ef8084bb-056f-4371-a0f5-e24296f45bb5 · outbound
Causal concept for black hole shadows TOPOLOGICAL CLASSIFICATION OF BLACK HOLES: GENERIC MAXWELL SET AND CREASE SET OF a HORIZON
Reference 77
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 9551010b-4871-4ae4-ba9d-ffe4c7273845 · outbound
Causal concept for black hole shadows Topology of event horizon in axially symmetric spacetime: Classification of maxwell set with symmetry
Reference 78
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 86117b24-ad24-45b9-ae8c-47eb2967e303 · outbound
Causal concept for black hole shadows Unresolved cited work
Reference 79
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation 89daf1dd-9f35-4fd2-9bf6-c56621139cf8 · outbound
Causal concept for black hole shadows Siino and D
Reference 80
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-15T06:32:42.880941+00:00.
Observation b0f5ac3e-7caf-4c8d-b2b5-74076f2f0cf7 · inbound
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 Causal concept for black hole shadows
Reference 53
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