{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:7OPFFYZCQVDPFEMWLN7RCJEQMU","short_pith_number":"pith:7OPFFYZC","canonical_record":{"source":{"id":"1202.4317","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-02-20T13:23:45Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"e5315f17ad555adb426113abe52fa0380cf0da36abaa23be4ceb3d545ea76e68","abstract_canon_sha256":"39f4d761a2c6fbfa303e23dd18b86bab105bcf7cdab6e82e2f3368227de2012f"},"schema_version":"1.0"},"canonical_sha256":"fb9e52e3228546f291965b7f11249065329af68578eaaab54efb779018f41b43","source":{"kind":"arxiv","id":"1202.4317","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1202.4317","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"arxiv_version","alias_value":"1202.4317v1","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1202.4317","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"pith_short_12","alias_value":"7OPFFYZCQVDP","created_at":"2026-05-18T12:26:58Z"},{"alias_kind":"pith_short_16","alias_value":"7OPFFYZCQVDPFEMW","created_at":"2026-05-18T12:26:58Z"},{"alias_kind":"pith_short_8","alias_value":"7OPFFYZC","created_at":"2026-05-18T12:26:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:7OPFFYZCQVDPFEMWLN7RCJEQMU","target":"record","payload":{"canonical_record":{"source":{"id":"1202.4317","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-02-20T13:23:45Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"e5315f17ad555adb426113abe52fa0380cf0da36abaa23be4ceb3d545ea76e68","abstract_canon_sha256":"39f4d761a2c6fbfa303e23dd18b86bab105bcf7cdab6e82e2f3368227de2012f"},"schema_version":"1.0"},"canonical_sha256":"fb9e52e3228546f291965b7f11249065329af68578eaaab54efb779018f41b43","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:37:02.915078Z","signature_b64":"Gmm+oJEM1a1aAXYk0ftprTGNffH91ktqDMctVSbE8h/gkdWPyyElWgInE/FNnuSDdbRF7mrmaLDx2KClnVWDDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fb9e52e3228546f291965b7f11249065329af68578eaaab54efb779018f41b43","last_reissued_at":"2026-05-18T00:37:02.914467Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:37:02.914467Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1202.4317","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":"2026-05-18T00:37:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uFXq+uvZDtyaYnIU5ROTxaqTF0b/ugKkiTqK18VRto5b7Ljzu3eQzj66yZbcrTCpwiTMmnJD57r1znsX9r7RBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T16:41:14.334532Z"},"content_sha256":"55c5a02870bfec1939c2e68c0aed1874a9ac66e6a339e0e608d9d988d3a75a90","schema_version":"1.0","event_id":"sha256:55c5a02870bfec1939c2e68c0aed1874a9ac66e6a339e0e608d9d988d3a75a90"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:7OPFFYZCQVDPFEMWLN7RCJEQMU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Equation of State for Dark Energy in Modified Gravity Theories","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"gr-qc","authors_text":"Kazuharu Bamba","submitted_at":"2012-02-20T13:23:45Z","abstract_excerpt":"We explore the equation of state (EoS) for dark energy $w_{\\mathrm{DE}}$ in modified gravitational theories to explain the current accelerated expansion of the universe. We explicitly demonstrate that the future crossings of the phantom divide line of $w_{\\mathrm{DE}}=-1$ are the generic feature in the existing viable $f(R)$ gravity models. Furthermore, we show that the crossing of the phantom divide can be realized in the combined $f(T)$ theory constructed with the exponential and logarithmic terms. In addition, we investigate the effective EoS for the universe when the finite-time future sin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1202.4317","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":"2026-05-18T00:37:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"r7HBf/z/6xg053nyh6R1tm2GPQeo+uNNcvgE0GfbWrrnrz8JagB5+as0BPYODZWYnEMGA0UK0QBuEeqDZYGYBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T16:41:14.334880Z"},"content_sha256":"97f6056f8aa3dbb836b0f5b501094dd427f94fcfeb27b44ca7753712cc67b6be","schema_version":"1.0","event_id":"sha256:97f6056f8aa3dbb836b0f5b501094dd427f94fcfeb27b44ca7753712cc67b6be"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/bundle.json","state_url":"https://pith.science/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/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":"2026-05-28T16:41:14Z","links":{"resolver":"https://pith.science/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU","bundle":"https://pith.science/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/bundle.json","state":"https://pith.science/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7OPFFYZCQVDPFEMWLN7RCJEQMU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:7OPFFYZCQVDPFEMWLN7RCJEQMU","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":"39f4d761a2c6fbfa303e23dd18b86bab105bcf7cdab6e82e2f3368227de2012f","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-02-20T13:23:45Z","title_canon_sha256":"e5315f17ad555adb426113abe52fa0380cf0da36abaa23be4ceb3d545ea76e68"},"schema_version":"1.0","source":{"id":"1202.4317","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1202.4317","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"arxiv_version","alias_value":"1202.4317v1","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1202.4317","created_at":"2026-05-18T00:37:02Z"},{"alias_kind":"pith_short_12","alias_value":"7OPFFYZCQVDP","created_at":"2026-05-18T12:26:58Z"},{"alias_kind":"pith_short_16","alias_value":"7OPFFYZCQVDPFEMW","created_at":"2026-05-18T12:26:58Z"},{"alias_kind":"pith_short_8","alias_value":"7OPFFYZC","created_at":"2026-05-18T12:26:58Z"}],"graph_snapshots":[{"event_id":"sha256:97f6056f8aa3dbb836b0f5b501094dd427f94fcfeb27b44ca7753712cc67b6be","target":"graph","created_at":"2026-05-18T00:37:02Z","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 explore the equation of state (EoS) for dark energy $w_{\\mathrm{DE}}$ in modified gravitational theories to explain the current accelerated expansion of the universe. We explicitly demonstrate that the future crossings of the phantom divide line of $w_{\\mathrm{DE}}=-1$ are the generic feature in the existing viable $f(R)$ gravity models. Furthermore, we show that the crossing of the phantom divide can be realized in the combined $f(T)$ theory constructed with the exponential and logarithmic terms. In addition, we investigate the effective EoS for the universe when the finite-time future sin","authors_text":"Kazuharu Bamba","cross_cats":["astro-ph.CO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-02-20T13:23:45Z","title":"Equation of State for Dark Energy in Modified Gravity Theories"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1202.4317","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":"sha256:55c5a02870bfec1939c2e68c0aed1874a9ac66e6a339e0e608d9d988d3a75a90","target":"record","created_at":"2026-05-18T00:37:02Z","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":"39f4d761a2c6fbfa303e23dd18b86bab105bcf7cdab6e82e2f3368227de2012f","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-02-20T13:23:45Z","title_canon_sha256":"e5315f17ad555adb426113abe52fa0380cf0da36abaa23be4ceb3d545ea76e68"},"schema_version":"1.0","source":{"id":"1202.4317","kind":"arxiv","version":1}},"canonical_sha256":"fb9e52e3228546f291965b7f11249065329af68578eaaab54efb779018f41b43","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fb9e52e3228546f291965b7f11249065329af68578eaaab54efb779018f41b43","first_computed_at":"2026-05-18T00:37:02.914467Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:37:02.914467Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Gmm+oJEM1a1aAXYk0ftprTGNffH91ktqDMctVSbE8h/gkdWPyyElWgInE/FNnuSDdbRF7mrmaLDx2KClnVWDDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:37:02.915078Z","signed_message":"canonical_sha256_bytes"},"source_id":"1202.4317","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:55c5a02870bfec1939c2e68c0aed1874a9ac66e6a339e0e608d9d988d3a75a90","sha256:97f6056f8aa3dbb836b0f5b501094dd427f94fcfeb27b44ca7753712cc67b6be"],"state_sha256":"11f763dbe4f9e76a4cf69ca16e026eaf082ddc1cd568b1246a38d2917702b40b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wsSYTzrbga38oCgA2ZkKdqX4Xl7f8U7fOGCx8mkOM0Szct3X9p5td7pIKV/qIsKhLsWtkxzF6+nICeq2JqDvDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T16:41:14.337079Z","bundle_sha256":"ccc539eee0ebb8a8831f2daf995d96ee348e8a41cbc6c7e6065666afb0683672"}}