{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:4GPVVSVBKZEWHCITCDS7QWVUIN","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":"a18da4c06b6a3d28137be7a2b5393b61b0e0a89b58ceba649075a13af4223b22","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-05-09T07:46:13Z","title_canon_sha256":"f32e30abe99dc801a52e77b4f673214b2abf4a2c024713d527cd059d09cc4b90"},"schema_version":"1.0","source":{"id":"1405.2163","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.2163","created_at":"2026-05-18T02:52:13Z"},{"alias_kind":"arxiv_version","alias_value":"1405.2163v1","created_at":"2026-05-18T02:52:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.2163","created_at":"2026-05-18T02:52:13Z"},{"alias_kind":"pith_short_12","alias_value":"4GPVVSVBKZEW","created_at":"2026-05-18T12:28:14Z"},{"alias_kind":"pith_short_16","alias_value":"4GPVVSVBKZEWHCIT","created_at":"2026-05-18T12:28:14Z"},{"alias_kind":"pith_short_8","alias_value":"4GPVVSVB","created_at":"2026-05-18T12:28:14Z"}],"graph_snapshots":[{"event_id":"sha256:1698e583fc203a6fdbaa422ffb7661aebba405f912a49ed49599cae133059fbe","target":"graph","created_at":"2026-05-18T02:52:13Z","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 study of degrees of freedom of signals observed within spatially diverse broadband multipath fields is an area of ongoing investigation and has a wide range of applications, including characterising broadband MIMO and cooperative networks. However, a fundamental question arises: given a size limitation on the observation region, what is the upper bound on the degrees of freedom of signals observed within a broadband multipath field over a finite time window? In order to address this question, we characterize the multipath field as a sum of a finite number of orthogonal waveforms or spatial","authors_text":"Farhana Bashar, S.M. Akramus Salehin, Thushara D. Abhayapala","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-05-09T07:46:13Z","title":"Band Limited Signals Observed Over Finite Spatial and Temporal Windows: An Upper Bound to Signal Degrees of Freedom"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.2163","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":"sha256:431daaf5162c02aa651a6b1194010283b75b5b951a13ebee0b0cdb0a50a648d2","target":"record","created_at":"2026-05-18T02:52:13Z","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":"a18da4c06b6a3d28137be7a2b5393b61b0e0a89b58ceba649075a13af4223b22","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2014-05-09T07:46:13Z","title_canon_sha256":"f32e30abe99dc801a52e77b4f673214b2abf4a2c024713d527cd059d09cc4b90"},"schema_version":"1.0","source":{"id":"1405.2163","kind":"arxiv","version":1}},"canonical_sha256":"e19f5acaa1564963891310e5f85ab44346c206a47a1d1a21d057a947d93a7323","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e19f5acaa1564963891310e5f85ab44346c206a47a1d1a21d057a947d93a7323","first_computed_at":"2026-05-18T02:52:13.490806Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:52:13.490806Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"EK3iMheUmTCTsx1VI1PO8MG87eVM9byGtL5IgU1zfxz+l6vCDjhbf6lLVqO+ZuGXBx+sLoxPZzkbyCZjC9QzBw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:52:13.491324Z","signed_message":"canonical_sha256_bytes"},"source_id":"1405.2163","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:431daaf5162c02aa651a6b1194010283b75b5b951a13ebee0b0cdb0a50a648d2","sha256:1698e583fc203a6fdbaa422ffb7661aebba405f912a49ed49599cae133059fbe"],"state_sha256":"a63039582b8684bf1f2035d6ed52c3fd42ef3409b06ae071fc7e658cc4b1f1d5"}