{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:X7LWAYQJ27LUR6EPR3KFXUYHEH","short_pith_number":"pith:X7LWAYQJ","canonical_record":{"source":{"id":"1508.00478","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2015-08-03T16:22:49Z","cross_cats_sorted":[],"title_canon_sha256":"1e4efdc18ce2318b10453adcdd410e1c99003c5d6459969164ad6dbcd0588368","abstract_canon_sha256":"fdd32910992c357171d03bd19439f9a4d610105c92501a7846e9e903f9434dda"},"schema_version":"1.0"},"canonical_sha256":"bfd7606209d7d748f88f8ed45bd30721ff31fbdc45807fa4bfc6b1803fcde8e1","source":{"kind":"arxiv","id":"1508.00478","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1508.00478","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"arxiv_version","alias_value":"1508.00478v1","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1508.00478","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"pith_short_12","alias_value":"X7LWAYQJ27LU","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_16","alias_value":"X7LWAYQJ27LUR6EP","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_8","alias_value":"X7LWAYQJ","created_at":"2026-05-18T12:29:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:X7LWAYQJ27LUR6EPR3KFXUYHEH","target":"record","payload":{"canonical_record":{"source":{"id":"1508.00478","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2015-08-03T16:22:49Z","cross_cats_sorted":[],"title_canon_sha256":"1e4efdc18ce2318b10453adcdd410e1c99003c5d6459969164ad6dbcd0588368","abstract_canon_sha256":"fdd32910992c357171d03bd19439f9a4d610105c92501a7846e9e903f9434dda"},"schema_version":"1.0"},"canonical_sha256":"bfd7606209d7d748f88f8ed45bd30721ff31fbdc45807fa4bfc6b1803fcde8e1","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:35:57.996470Z","signature_b64":"uqMFmkpCcJFCKzZtCfgXqu96uALdx/WXcxDRAErmy+79KqDYAMQaopdQYmHtiXcC4umS310VjEqYmjHBWo3SBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"bfd7606209d7d748f88f8ed45bd30721ff31fbdc45807fa4bfc6b1803fcde8e1","last_reissued_at":"2026-05-18T01:35:57.995688Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:35:57.995688Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1508.00478","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:35:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"OZLnxp5cA82gX9jwU3UDY0dY/14gm2S2fZO70lVctFNSbUYPr8r182ivmTtMdd4iFh5RMkJwdnS/OeuCs4SpDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-24T15:13:47.917981Z"},"content_sha256":"574bf45ff5ff85309e2b9306e4c4544dfb4e8ca757642d32eed6d947353fa9f9","schema_version":"1.0","event_id":"sha256:574bf45ff5ff85309e2b9306e4c4544dfb4e8ca757642d32eed6d947353fa9f9"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:X7LWAYQJ27LUR6EPR3KFXUYHEH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The superfluid phase transition in two-dimensional excitonic systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.str-el","authors_text":"T.K. Kope\\'c, V. Apinyan","submitted_at":"2015-08-03T16:22:49Z","abstract_excerpt":"We study the superfluid phase transition in the two-dimensional (2D) excitonic system. Employing the extended Falicov-Kimball model (EFKM) and considering the local quantum correlations in the system composed of conduction band electrons and valence band holes we demonstrate the existence of the excitonic insulator (EI) state in the system. We show that at very low temperatures, the particle phase stiffness in the pure-2D excitonic system, governed by the non-local cross correlations, is responsible for the vortex-antivortex binding phase-field state, known as the Berezinskii-Kosterlitz-Thoule"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1508.00478","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:35:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bWjRBaNMkzWIEikAGAPlr3TFJGsF50IKIibcKXqClQ3bVqqS3ey0/ubvusIaDIaPYnObBLoDVsf+EV/rwOJCDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-24T15:13:47.918336Z"},"content_sha256":"776b9498adea9bba4a481e511c363aaedf283c8f4959558c597021c27b069efb","schema_version":"1.0","event_id":"sha256:776b9498adea9bba4a481e511c363aaedf283c8f4959558c597021c27b069efb"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/bundle.json","state_url":"https://pith.science/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-24T15:13:47Z","links":{"resolver":"https://pith.science/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH","bundle":"https://pith.science/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/bundle.json","state":"https://pith.science/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/X7LWAYQJ27LUR6EPR3KFXUYHEH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:X7LWAYQJ27LUR6EPR3KFXUYHEH","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"fdd32910992c357171d03bd19439f9a4d610105c92501a7846e9e903f9434dda","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2015-08-03T16:22:49Z","title_canon_sha256":"1e4efdc18ce2318b10453adcdd410e1c99003c5d6459969164ad6dbcd0588368"},"schema_version":"1.0","source":{"id":"1508.00478","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1508.00478","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"arxiv_version","alias_value":"1508.00478v1","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1508.00478","created_at":"2026-05-18T01:35:57Z"},{"alias_kind":"pith_short_12","alias_value":"X7LWAYQJ27LU","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_16","alias_value":"X7LWAYQJ27LUR6EP","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_8","alias_value":"X7LWAYQJ","created_at":"2026-05-18T12:29:50Z"}],"graph_snapshots":[{"event_id":"sha256:776b9498adea9bba4a481e511c363aaedf283c8f4959558c597021c27b069efb","target":"graph","created_at":"2026-05-18T01:35:57Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"We study the superfluid phase transition in the two-dimensional (2D) excitonic system. Employing the extended Falicov-Kimball model (EFKM) and considering the local quantum correlations in the system composed of conduction band electrons and valence band holes we demonstrate the existence of the excitonic insulator (EI) state in the system. We show that at very low temperatures, the particle phase stiffness in the pure-2D excitonic system, governed by the non-local cross correlations, is responsible for the vortex-antivortex binding phase-field state, known as the Berezinskii-Kosterlitz-Thoule","authors_text":"T.K. Kope\\'c, V. Apinyan","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2015-08-03T16:22:49Z","title":"The superfluid phase transition in two-dimensional excitonic systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1508.00478","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:574bf45ff5ff85309e2b9306e4c4544dfb4e8ca757642d32eed6d947353fa9f9","target":"record","created_at":"2026-05-18T01:35:57Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"fdd32910992c357171d03bd19439f9a4d610105c92501a7846e9e903f9434dda","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2015-08-03T16:22:49Z","title_canon_sha256":"1e4efdc18ce2318b10453adcdd410e1c99003c5d6459969164ad6dbcd0588368"},"schema_version":"1.0","source":{"id":"1508.00478","kind":"arxiv","version":1}},"canonical_sha256":"bfd7606209d7d748f88f8ed45bd30721ff31fbdc45807fa4bfc6b1803fcde8e1","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"bfd7606209d7d748f88f8ed45bd30721ff31fbdc45807fa4bfc6b1803fcde8e1","first_computed_at":"2026-05-18T01:35:57.995688Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:35:57.995688Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"uqMFmkpCcJFCKzZtCfgXqu96uALdx/WXcxDRAErmy+79KqDYAMQaopdQYmHtiXcC4umS310VjEqYmjHBWo3SBA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:35:57.996470Z","signed_message":"canonical_sha256_bytes"},"source_id":"1508.00478","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:574bf45ff5ff85309e2b9306e4c4544dfb4e8ca757642d32eed6d947353fa9f9","sha256:776b9498adea9bba4a481e511c363aaedf283c8f4959558c597021c27b069efb"],"state_sha256":"e87f21d4d709661161f831c6161685ae6d401817b0d7bccbfa63f357797ee280"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uOo1pPWik++8lV6oRGMQT6koLdbiVwmFwdQkI2jJiTByoStohqblBk2IU0m4XQSE44SuWVUpjVQJ+21OYDLPAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-24T15:13:47.920257Z","bundle_sha256":"e68fa30b474f0ff0d3b478304ebe00f64e76838b99f66f60f71a6f41af6aea27"}}