{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:MBW3HL3Z5VBBSJOKU66YNZAV67","short_pith_number":"pith:MBW3HL3Z","canonical_record":{"source":{"id":"1109.5701","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2011-09-26T20:00:06Z","cross_cats_sorted":[],"title_canon_sha256":"3e64761b4d1bc87a20a366698c85acf41a1326e2c5d5c14c3e908c163f39e657","abstract_canon_sha256":"490bc2d0e8aeeeb9dafbf8b67cd1eaa77fea539a0060f6a9ced3a1be04534e45"},"schema_version":"1.0"},"canonical_sha256":"606db3af79ed421925caa7bd86e415f7efd186adc961ab7bf55a6bf9ecf05f7f","source":{"kind":"arxiv","id":"1109.5701","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1109.5701","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"arxiv_version","alias_value":"1109.5701v2","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1109.5701","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"pith_short_12","alias_value":"MBW3HL3Z5VBB","created_at":"2026-05-18T12:26:34Z"},{"alias_kind":"pith_short_16","alias_value":"MBW3HL3Z5VBBSJOK","created_at":"2026-05-18T12:26:34Z"},{"alias_kind":"pith_short_8","alias_value":"MBW3HL3Z","created_at":"2026-05-18T12:26:34Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:MBW3HL3Z5VBBSJOKU66YNZAV67","target":"record","payload":{"canonical_record":{"source":{"id":"1109.5701","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2011-09-26T20:00:06Z","cross_cats_sorted":[],"title_canon_sha256":"3e64761b4d1bc87a20a366698c85acf41a1326e2c5d5c14c3e908c163f39e657","abstract_canon_sha256":"490bc2d0e8aeeeb9dafbf8b67cd1eaa77fea539a0060f6a9ced3a1be04534e45"},"schema_version":"1.0"},"canonical_sha256":"606db3af79ed421925caa7bd86e415f7efd186adc961ab7bf55a6bf9ecf05f7f","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:07:17.441519Z","signature_b64":"67Miy/ewEUWnobw4Yzl4R+tyf03N6l2Zk3paOJ9ua5+BrxkHYxLgDJ32VzAtikEy6yhc/9oyhT36k0KEWtsiBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"606db3af79ed421925caa7bd86e415f7efd186adc961ab7bf55a6bf9ecf05f7f","last_reissued_at":"2026-05-18T04:07:17.440833Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:07:17.440833Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1109.5701","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":"2026-05-18T04:07:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"H5RnmfeYD0+Uba+aeL+UB3fnXvBKI/W02e/7gCCxLgAAhVxuqHp4rzyUQclk67Dl/H7lgkv2MYR/Nde5y9q2CQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:22:48.122735Z"},"content_sha256":"16b6574bc6fb0cd0f97f229305dddbeb2a2c65f562fbb55a752480ef5c1cb9f7","schema_version":"1.0","event_id":"sha256:16b6574bc6fb0cd0f97f229305dddbeb2a2c65f562fbb55a752480ef5c1cb9f7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:MBW3HL3Z5VBBSJOKU66YNZAV67","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Temperature-dependent compressibility in graphene and two-dimensional systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mes-hall","authors_text":"E. H. Hwang, Qiuzi Li, S. Das Sarma","submitted_at":"2011-09-26T20:00:06Z","abstract_excerpt":"We calculate the finite temperature compressibility for two-dimensional semiconductor systems, monolayer graphene, and bilayer graphene within the Hartree-Fock approximation. We find that the calculated temperature dependent compressibility including exchange energy is non-monotonic. In 2D systems at low temperatures the inverse compressibility decreases first with increasing temperature, but after reaching a minimum it increases as temperature is raised further. At high enough temperatures the negative compressibility of low density systems induced by the exchange energy becomes positive due "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.5701","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":"2026-05-18T04:07:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wn9xo/XsgKjIcYuP8fMZGAIIDLWA+qE0qmGopE9wpnHaic1V+qFe8En4JPgdSLCptXD3FWehN0QjIjL/MUv3Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:22:48.123484Z"},"content_sha256":"1a316660b1651730426f74f948f18ec12df75d9070acb9f3a8b124216dc3864e","schema_version":"1.0","event_id":"sha256:1a316660b1651730426f74f948f18ec12df75d9070acb9f3a8b124216dc3864e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/bundle.json","state_url":"https://pith.science/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/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":"2026-05-25T17:22:48Z","links":{"resolver":"https://pith.science/pith/MBW3HL3Z5VBBSJOKU66YNZAV67","bundle":"https://pith.science/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/bundle.json","state":"https://pith.science/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MBW3HL3Z5VBBSJOKU66YNZAV67/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:MBW3HL3Z5VBBSJOKU66YNZAV67","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":"490bc2d0e8aeeeb9dafbf8b67cd1eaa77fea539a0060f6a9ced3a1be04534e45","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2011-09-26T20:00:06Z","title_canon_sha256":"3e64761b4d1bc87a20a366698c85acf41a1326e2c5d5c14c3e908c163f39e657"},"schema_version":"1.0","source":{"id":"1109.5701","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1109.5701","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"arxiv_version","alias_value":"1109.5701v2","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1109.5701","created_at":"2026-05-18T04:07:17Z"},{"alias_kind":"pith_short_12","alias_value":"MBW3HL3Z5VBB","created_at":"2026-05-18T12:26:34Z"},{"alias_kind":"pith_short_16","alias_value":"MBW3HL3Z5VBBSJOK","created_at":"2026-05-18T12:26:34Z"},{"alias_kind":"pith_short_8","alias_value":"MBW3HL3Z","created_at":"2026-05-18T12:26:34Z"}],"graph_snapshots":[{"event_id":"sha256:1a316660b1651730426f74f948f18ec12df75d9070acb9f3a8b124216dc3864e","target":"graph","created_at":"2026-05-18T04:07:17Z","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 calculate the finite temperature compressibility for two-dimensional semiconductor systems, monolayer graphene, and bilayer graphene within the Hartree-Fock approximation. We find that the calculated temperature dependent compressibility including exchange energy is non-monotonic. In 2D systems at low temperatures the inverse compressibility decreases first with increasing temperature, but after reaching a minimum it increases as temperature is raised further. At high enough temperatures the negative compressibility of low density systems induced by the exchange energy becomes positive due ","authors_text":"E. H. Hwang, Qiuzi Li, S. Das Sarma","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2011-09-26T20:00:06Z","title":"Temperature-dependent compressibility in graphene and two-dimensional systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.5701","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":"sha256:16b6574bc6fb0cd0f97f229305dddbeb2a2c65f562fbb55a752480ef5c1cb9f7","target":"record","created_at":"2026-05-18T04:07:17Z","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":"490bc2d0e8aeeeb9dafbf8b67cd1eaa77fea539a0060f6a9ced3a1be04534e45","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2011-09-26T20:00:06Z","title_canon_sha256":"3e64761b4d1bc87a20a366698c85acf41a1326e2c5d5c14c3e908c163f39e657"},"schema_version":"1.0","source":{"id":"1109.5701","kind":"arxiv","version":2}},"canonical_sha256":"606db3af79ed421925caa7bd86e415f7efd186adc961ab7bf55a6bf9ecf05f7f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"606db3af79ed421925caa7bd86e415f7efd186adc961ab7bf55a6bf9ecf05f7f","first_computed_at":"2026-05-18T04:07:17.440833Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:07:17.440833Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"67Miy/ewEUWnobw4Yzl4R+tyf03N6l2Zk3paOJ9ua5+BrxkHYxLgDJ32VzAtikEy6yhc/9oyhT36k0KEWtsiBg==","signature_status":"signed_v1","signed_at":"2026-05-18T04:07:17.441519Z","signed_message":"canonical_sha256_bytes"},"source_id":"1109.5701","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:16b6574bc6fb0cd0f97f229305dddbeb2a2c65f562fbb55a752480ef5c1cb9f7","sha256:1a316660b1651730426f74f948f18ec12df75d9070acb9f3a8b124216dc3864e"],"state_sha256":"6e1e88ab518403f8b3663e2918bb73ce37d057ef376d33e0f43b24d6b579188e"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HVHL8hmD9fNNQWP25pMseuvmT9EuD3n9N/bt7pSkpFjOgUTsFQz2mXVmCwRdAvSgw3Sf4/GZSpWrDkXuFeKHBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T17:22:48.127413Z","bundle_sha256":"24a5509de0f0c30f00c6d4a4fb9f57d648ddf567d55bb7d2cbde2578f871a1ea"}}