{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2010:26724JRRT2IXTZPEAZIYLALTHP","short_pith_number":"pith:26724JRR","canonical_record":{"source":{"id":"1012.3171","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2010-12-14T21:02:10Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"08b3462748b19ecc4c61b6dc256ae65a6acf47ad413925b74283b9e03fc1de1d","abstract_canon_sha256":"28ef2f6cc2396f6bdc3789578086049c20d344872f71bbe934d77501074ae53a"},"schema_version":"1.0"},"canonical_sha256":"d7bfae26319e9179e5e406518581733bec3a7580aa69a34e645e6994c481920e","source":{"kind":"arxiv","id":"1012.3171","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1012.3171","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"arxiv_version","alias_value":"1012.3171v2","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1012.3171","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"pith_short_12","alias_value":"26724JRRT2IX","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"26724JRRT2IXTZPE","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"26724JRR","created_at":"2026-05-18T12:26:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2010:26724JRRT2IXTZPEAZIYLALTHP","target":"record","payload":{"canonical_record":{"source":{"id":"1012.3171","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2010-12-14T21:02:10Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"08b3462748b19ecc4c61b6dc256ae65a6acf47ad413925b74283b9e03fc1de1d","abstract_canon_sha256":"28ef2f6cc2396f6bdc3789578086049c20d344872f71bbe934d77501074ae53a"},"schema_version":"1.0"},"canonical_sha256":"d7bfae26319e9179e5e406518581733bec3a7580aa69a34e645e6994c481920e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:22:39.972387Z","signature_b64":"ArHOqyh8en6+GvKbpvzTGNq9mtVa6xvDnUcDolOZrqaNYIynbHe5dbQWwY10AlKfu8AW+ndKGICa9VtJmGe3CQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d7bfae26319e9179e5e406518581733bec3a7580aa69a34e645e6994c481920e","last_reissued_at":"2026-05-18T04:22:39.972007Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:22:39.972007Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1012.3171","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T04:22:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ff9fToATmVErDVBwNzfV+bBqmJzcQHXlxmZwrHm4QaufuhcfBH+FFW3FiGqxcPXdtKx1VWdfYukbFfzF4NiNDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:09:45.342962Z"},"content_sha256":"ca3db2ff57664ca12fef6955415a4ba549d17c1362696204ba10828661d30faa","schema_version":"1.0","event_id":"sha256:ca3db2ff57664ca12fef6955415a4ba549d17c1362696204ba10828661d30faa"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2010:26724JRRT2IXTZPEAZIYLALTHP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Anisotropic stress and stability in modified gravity models","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"gr-qc","authors_text":"Ippocratis D. Saltas, Martin Kunz","submitted_at":"2010-12-14T21:02:10Z","abstract_excerpt":"The existence of anisotropic stress of a purely geometrical origin seems to be a characteristic of higher order gravity models, and has been suggested as a probe to test these models observationally, for example in weak lensing experiments. In this paper, we seek to find a class of higher order gravity models of f(R,G) type that would give us a zero anisotropic stress and study the consequences for the viability of the actual model. For the special case of a de Sitter background, we identify a subclass of models with the desired property. We also find a direct link between anisotropic stress a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1012.3171","kind":"arxiv","version":2},"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":"2026-05-18T04:22:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4oOjFlvtMhJQGZVj/ZnTDisPX1p632GUEPmgLCwwXoBjGkabjQvevqb9ftDBwNf4wPsZ5jpx+dBkVl8zGcQpDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:09:45.343310Z"},"content_sha256":"47fb9a07a0970ac0fc569e6964edabec51e5dbf8bda30c585e085867a3283a54","schema_version":"1.0","event_id":"sha256:47fb9a07a0970ac0fc569e6964edabec51e5dbf8bda30c585e085867a3283a54"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/26724JRRT2IXTZPEAZIYLALTHP/bundle.json","state_url":"https://pith.science/pith/26724JRRT2IXTZPEAZIYLALTHP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/26724JRRT2IXTZPEAZIYLALTHP/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":"2026-05-28T14:09:45Z","links":{"resolver":"https://pith.science/pith/26724JRRT2IXTZPEAZIYLALTHP","bundle":"https://pith.science/pith/26724JRRT2IXTZPEAZIYLALTHP/bundle.json","state":"https://pith.science/pith/26724JRRT2IXTZPEAZIYLALTHP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/26724JRRT2IXTZPEAZIYLALTHP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:26724JRRT2IXTZPEAZIYLALTHP","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":"28ef2f6cc2396f6bdc3789578086049c20d344872f71bbe934d77501074ae53a","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2010-12-14T21:02:10Z","title_canon_sha256":"08b3462748b19ecc4c61b6dc256ae65a6acf47ad413925b74283b9e03fc1de1d"},"schema_version":"1.0","source":{"id":"1012.3171","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1012.3171","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"arxiv_version","alias_value":"1012.3171v2","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1012.3171","created_at":"2026-05-18T04:22:39Z"},{"alias_kind":"pith_short_12","alias_value":"26724JRRT2IX","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"26724JRRT2IXTZPE","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"26724JRR","created_at":"2026-05-18T12:26:03Z"}],"graph_snapshots":[{"event_id":"sha256:47fb9a07a0970ac0fc569e6964edabec51e5dbf8bda30c585e085867a3283a54","target":"graph","created_at":"2026-05-18T04:22:39Z","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":"The existence of anisotropic stress of a purely geometrical origin seems to be a characteristic of higher order gravity models, and has been suggested as a probe to test these models observationally, for example in weak lensing experiments. In this paper, we seek to find a class of higher order gravity models of f(R,G) type that would give us a zero anisotropic stress and study the consequences for the viability of the actual model. For the special case of a de Sitter background, we identify a subclass of models with the desired property. We also find a direct link between anisotropic stress a","authors_text":"Ippocratis D. Saltas, Martin Kunz","cross_cats":["astro-ph.CO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2010-12-14T21:02:10Z","title":"Anisotropic stress and stability in modified gravity models"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1012.3171","kind":"arxiv","version":2},"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:ca3db2ff57664ca12fef6955415a4ba549d17c1362696204ba10828661d30faa","target":"record","created_at":"2026-05-18T04:22:39Z","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":"28ef2f6cc2396f6bdc3789578086049c20d344872f71bbe934d77501074ae53a","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2010-12-14T21:02:10Z","title_canon_sha256":"08b3462748b19ecc4c61b6dc256ae65a6acf47ad413925b74283b9e03fc1de1d"},"schema_version":"1.0","source":{"id":"1012.3171","kind":"arxiv","version":2}},"canonical_sha256":"d7bfae26319e9179e5e406518581733bec3a7580aa69a34e645e6994c481920e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d7bfae26319e9179e5e406518581733bec3a7580aa69a34e645e6994c481920e","first_computed_at":"2026-05-18T04:22:39.972007Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:22:39.972007Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ArHOqyh8en6+GvKbpvzTGNq9mtVa6xvDnUcDolOZrqaNYIynbHe5dbQWwY10AlKfu8AW+ndKGICa9VtJmGe3CQ==","signature_status":"signed_v1","signed_at":"2026-05-18T04:22:39.972387Z","signed_message":"canonical_sha256_bytes"},"source_id":"1012.3171","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ca3db2ff57664ca12fef6955415a4ba549d17c1362696204ba10828661d30faa","sha256:47fb9a07a0970ac0fc569e6964edabec51e5dbf8bda30c585e085867a3283a54"],"state_sha256":"65fbe064aee681e590a538728618fd3cadcc4442e7372b0329fb5a6f7f0cfd5c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"3coyXfZJWjsxgjAq8i4V9wl7eg5Jkz6JlFE0fEyH6/PMZFdRaQDJNidtRPkeWPYWZnlHT40Ou2imaAkeSTQ0BA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T14:09:45.345392Z","bundle_sha256":"2b639512c040f6116e761e528797c16a7bd7c21a70241cebc27e2a912b8bca64"}}