{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:2ARVHXI23W5Q4N6DTAYECQK2U4","short_pith_number":"pith:2ARVHXI2","canonical_record":{"source":{"id":"1801.05246","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math-ph","submitted_at":"2018-01-16T13:27:51Z","cross_cats_sorted":["math.MP"],"title_canon_sha256":"2f3302a3cb080942e8cfe3eace113fd9214159f5fca7e8314557f4db6756376c","abstract_canon_sha256":"938230e1fd5b693598154d1089a9afaea5752007c92891d574cba91126495f5e"},"schema_version":"1.0"},"canonical_sha256":"d02353dd1addbb0e37c3983041415aa73ef2367dac3dc5a616b35c5ef7e6b539","source":{"kind":"arxiv","id":"1801.05246","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.05246","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"arxiv_version","alias_value":"1801.05246v1","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.05246","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"pith_short_12","alias_value":"2ARVHXI23W5Q","created_at":"2026-05-18T12:31:59Z"},{"alias_kind":"pith_short_16","alias_value":"2ARVHXI23W5Q4N6D","created_at":"2026-05-18T12:31:59Z"},{"alias_kind":"pith_short_8","alias_value":"2ARVHXI2","created_at":"2026-05-18T12:31:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:2ARVHXI23W5Q4N6DTAYECQK2U4","target":"record","payload":{"canonical_record":{"source":{"id":"1801.05246","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math-ph","submitted_at":"2018-01-16T13:27:51Z","cross_cats_sorted":["math.MP"],"title_canon_sha256":"2f3302a3cb080942e8cfe3eace113fd9214159f5fca7e8314557f4db6756376c","abstract_canon_sha256":"938230e1fd5b693598154d1089a9afaea5752007c92891d574cba91126495f5e"},"schema_version":"1.0"},"canonical_sha256":"d02353dd1addbb0e37c3983041415aa73ef2367dac3dc5a616b35c5ef7e6b539","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:13:30.334936Z","signature_b64":"NXnBYPSB5SgCIgQXEXGT1rhnsp9ynPdouPloeGlUKY0eYzWucL+98Yt/gNihF5FQiUPhgGHKXVcmX5mYrZa5BA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d02353dd1addbb0e37c3983041415aa73ef2367dac3dc5a616b35c5ef7e6b539","last_reissued_at":"2026-05-18T00:13:30.334287Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:13:30.334287Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1801.05246","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":"2026-05-18T00:13:30Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Q68E8ogtCfGQ+iKqutzIMvqjrPYqtxGQ0vlgzUe0pBBAS6rNCWQJdFXxIWZfQux9XwxzimjnwcPwRQQYlDfwAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T03:09:02.558509Z"},"content_sha256":"b85db62a6cacc4a7e70be030b940290d086bff6216f8d42a955395d7f23d2a10","schema_version":"1.0","event_id":"sha256:b85db62a6cacc4a7e70be030b940290d086bff6216f8d42a955395d7f23d2a10"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:2ARVHXI23W5Q4N6DTAYECQK2U4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Isospectral discrete and quantum graphs with the same flip counts and nodal counts","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.MP"],"primary_cat":"math-ph","authors_text":"Christopher H. Joyner, Jonas S. Juul","submitted_at":"2018-01-16T13:27:51Z","abstract_excerpt":"The existence of non-isomorphic graphs which share the same Laplace spectrum (to be referred to as isospectral graphs) leads naturally to the following question: What additional information is required in order to resolve isospectral graphs? It was suggested by Band, Shapira and Smilansky that this might be achieved by either counting the number of nodal domains or the number of times the eigenfunctions change sign (the so-called flip count). Recently examples of (discrete) isospectral graphs with the same flip count and nodal count have been constructed by K. Ammann by utilising Godsil-McKay "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.05246","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":"2026-05-18T00:13:30Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"i876SAXGkLZNhYn1oICZVkZ/+gUPEDEI9yO4BQKkSAS43/QWExg6Ye+u3zQXADYYGM3KS94QvIlEUUR/dEojCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T03:09:02.559207Z"},"content_sha256":"d1f711f440be34b7efca5d02983644bd57b6692989da5c8b11a8549ed9b1394b","schema_version":"1.0","event_id":"sha256:d1f711f440be34b7efca5d02983644bd57b6692989da5c8b11a8549ed9b1394b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/bundle.json","state_url":"https://pith.science/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/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":"2026-05-25T03:09:02Z","links":{"resolver":"https://pith.science/pith/2ARVHXI23W5Q4N6DTAYECQK2U4","bundle":"https://pith.science/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/bundle.json","state":"https://pith.science/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/2ARVHXI23W5Q4N6DTAYECQK2U4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:2ARVHXI23W5Q4N6DTAYECQK2U4","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":"938230e1fd5b693598154d1089a9afaea5752007c92891d574cba91126495f5e","cross_cats_sorted":["math.MP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math-ph","submitted_at":"2018-01-16T13:27:51Z","title_canon_sha256":"2f3302a3cb080942e8cfe3eace113fd9214159f5fca7e8314557f4db6756376c"},"schema_version":"1.0","source":{"id":"1801.05246","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.05246","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"arxiv_version","alias_value":"1801.05246v1","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.05246","created_at":"2026-05-18T00:13:30Z"},{"alias_kind":"pith_short_12","alias_value":"2ARVHXI23W5Q","created_at":"2026-05-18T12:31:59Z"},{"alias_kind":"pith_short_16","alias_value":"2ARVHXI23W5Q4N6D","created_at":"2026-05-18T12:31:59Z"},{"alias_kind":"pith_short_8","alias_value":"2ARVHXI2","created_at":"2026-05-18T12:31:59Z"}],"graph_snapshots":[{"event_id":"sha256:d1f711f440be34b7efca5d02983644bd57b6692989da5c8b11a8549ed9b1394b","target":"graph","created_at":"2026-05-18T00:13:30Z","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 non-isomorphic graphs which share the same Laplace spectrum (to be referred to as isospectral graphs) leads naturally to the following question: What additional information is required in order to resolve isospectral graphs? It was suggested by Band, Shapira and Smilansky that this might be achieved by either counting the number of nodal domains or the number of times the eigenfunctions change sign (the so-called flip count). Recently examples of (discrete) isospectral graphs with the same flip count and nodal count have been constructed by K. Ammann by utilising Godsil-McKay ","authors_text":"Christopher H. Joyner, Jonas S. Juul","cross_cats":["math.MP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math-ph","submitted_at":"2018-01-16T13:27:51Z","title":"Isospectral discrete and quantum graphs with the same flip counts and nodal counts"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.05246","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:b85db62a6cacc4a7e70be030b940290d086bff6216f8d42a955395d7f23d2a10","target":"record","created_at":"2026-05-18T00:13:30Z","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":"938230e1fd5b693598154d1089a9afaea5752007c92891d574cba91126495f5e","cross_cats_sorted":["math.MP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math-ph","submitted_at":"2018-01-16T13:27:51Z","title_canon_sha256":"2f3302a3cb080942e8cfe3eace113fd9214159f5fca7e8314557f4db6756376c"},"schema_version":"1.0","source":{"id":"1801.05246","kind":"arxiv","version":1}},"canonical_sha256":"d02353dd1addbb0e37c3983041415aa73ef2367dac3dc5a616b35c5ef7e6b539","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d02353dd1addbb0e37c3983041415aa73ef2367dac3dc5a616b35c5ef7e6b539","first_computed_at":"2026-05-18T00:13:30.334287Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:13:30.334287Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"NXnBYPSB5SgCIgQXEXGT1rhnsp9ynPdouPloeGlUKY0eYzWucL+98Yt/gNihF5FQiUPhgGHKXVcmX5mYrZa5BA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:13:30.334936Z","signed_message":"canonical_sha256_bytes"},"source_id":"1801.05246","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b85db62a6cacc4a7e70be030b940290d086bff6216f8d42a955395d7f23d2a10","sha256:d1f711f440be34b7efca5d02983644bd57b6692989da5c8b11a8549ed9b1394b"],"state_sha256":"bfe1d23423a6ec16b9920e6508c5c94ac7c3ab572c86bde745182e8a329e930b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hn7625My+gjfS6blzAl+XRWYbhG2U5kIgn/DgzhIrCxozem5ltaxhDdc+DLKNAsiGP5ajyjvBlbsoURsNEWkBA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T03:09:02.562387Z","bundle_sha256":"efe7bc3c2d055a6a3bef585a82065263936442cf34d74a77c6d20614fa6db169"}}