{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:P7RGELECIWPDMBUWDZQHKXFA6W","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":"1ded6b1ed24dfde6a50ef3fcac7a593e38a5243e1ee9a31a4714da14aa946c75","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-09-27T21:25:26Z","title_canon_sha256":"7f1917f52680ef51090a4119540c75925bf7f2879feb7ed6ad30039aba9ab950"},"schema_version":"1.0","source":{"id":"1809.10773","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1809.10773","created_at":"2026-05-17T23:39:48Z"},{"alias_kind":"arxiv_version","alias_value":"1809.10773v1","created_at":"2026-05-17T23:39:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1809.10773","created_at":"2026-05-17T23:39:48Z"},{"alias_kind":"pith_short_12","alias_value":"P7RGELECIWPD","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_16","alias_value":"P7RGELECIWPDMBUW","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_8","alias_value":"P7RGELEC","created_at":"2026-05-18T12:32:43Z"}],"graph_snapshots":[{"event_id":"sha256:85a47d732d33e2e4f7667e0a475a180188e7fb95f14b983d72a9b7314a82bd7e","target":"graph","created_at":"2026-05-17T23:39:48Z","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 present a microscopic picture rationalizing the surprisingly steep decrease of the band gap with temperature in insulators, crystalline or otherwise. The gap narrowing largely results from fluctuations of long-wavelength optical phonons---when the latter are present---or their disordered analogs, if the material is amorphous. We elaborate on this notion to show that possibly with the exception of weakly bound solids made of closed-shell atoms, the existence of an insulating gap or pseudo-gap in a periodic solid implies that optical phonons must be present, too. This means that in an insulat","authors_text":"Arkady Kurnosov, Vassiliy Lubchenko","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-09-27T21:25:26Z","title":"Temperature-driven narrowing of the insulating gap as a precursor of the insulator-to-metal transition: Implications for the electronic structure of solids"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.10773","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:bbc5639ac634cebbd8bd90fde8588257e538ebc3ee2087866581c9468869b7df","target":"record","created_at":"2026-05-17T23:39:48Z","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":"1ded6b1ed24dfde6a50ef3fcac7a593e38a5243e1ee9a31a4714da14aa946c75","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-09-27T21:25:26Z","title_canon_sha256":"7f1917f52680ef51090a4119540c75925bf7f2879feb7ed6ad30039aba9ab950"},"schema_version":"1.0","source":{"id":"1809.10773","kind":"arxiv","version":1}},"canonical_sha256":"7fe2622c82459e3606961e60755ca0f5acf35183112514166de5803ffbc2bf23","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7fe2622c82459e3606961e60755ca0f5acf35183112514166de5803ffbc2bf23","first_computed_at":"2026-05-17T23:39:48.407938Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:39:48.407938Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"IfYl2wtP2o1ouxcKmf5n79K3M0fcC3FOPgJDbbV6LxfqondCbnbhsGp1x1h0ySGaXWFK6j0BLLW3qMNuVfR9Bw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:39:48.408567Z","signed_message":"canonical_sha256_bytes"},"source_id":"1809.10773","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:bbc5639ac634cebbd8bd90fde8588257e538ebc3ee2087866581c9468869b7df","sha256:85a47d732d33e2e4f7667e0a475a180188e7fb95f14b983d72a9b7314a82bd7e"],"state_sha256":"1e25f1c9645e88d6f74ef7e42932a0b9087a96ab4937344d031048594055645e"}