{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2011:QLDNPR7572FQYCI3NZVJDTOCDH","short_pith_number":"pith:QLDNPR75","schema_version":"1.0","canonical_sha256":"82c6d7c7fdfe8b0c091b6e6a91cdc219f87a9e240698c7b7d3abf4382b563a80","source":{"kind":"arxiv","id":"1109.0448","version":2},"attestation_state":"computed","paper":{"title":"Tilted Ekpyrosis","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"hep-th","authors_text":"David Wands (ICG, Jos\\'e Fonseca, Portsmouth)","submitted_at":"2011-09-02T14:04:35Z","abstract_excerpt":"We consider a simple model of cosmological collapse driven by canonical fields with exponential potentials. We generalise the two-field ekpyrotic collapse to consider non-orthogonal or tilted potentials and give the general condition for isocurvature field fluctuations to have a scale-invariant spectrum in this model. In particular we show that tilted potentials allow for a slightly red spectrum of perturbations as required by current observations. However a red spectrum of fluctuations implies that the two-field ekpyrotic phase must have a finite duration and requires a preceding phase which "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1109.0448","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-th","submitted_at":"2011-09-02T14:04:35Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"202c59b787db49f80047623bdd5843341ba827ef457c344df1eebacdf32e603b","abstract_canon_sha256":"018a587d87f03cd2438ca930d6e7f2b911dd5b1347177289c2ee145d65b4dfc2"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:23:21.451742Z","signature_b64":"MAlMOrw33go3ajJutmODaF9sySFpViOuCHl0hkV8q6ZpyMiOY7VSK4FEKX2PWOJ6gjJ+kS4E2IsZ6NYaDlgyCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"82c6d7c7fdfe8b0c091b6e6a91cdc219f87a9e240698c7b7d3abf4382b563a80","last_reissued_at":"2026-05-18T03:23:21.451234Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:23:21.451234Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Tilted Ekpyrosis","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"hep-th","authors_text":"David Wands (ICG, Jos\\'e Fonseca, Portsmouth)","submitted_at":"2011-09-02T14:04:35Z","abstract_excerpt":"We consider a simple model of cosmological collapse driven by canonical fields with exponential potentials. We generalise the two-field ekpyrotic collapse to consider non-orthogonal or tilted potentials and give the general condition for isocurvature field fluctuations to have a scale-invariant spectrum in this model. In particular we show that tilted potentials allow for a slightly red spectrum of perturbations as required by current observations. However a red spectrum of fluctuations implies that the two-field ekpyrotic phase must have a finite duration and requires a preceding phase which "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.0448","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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1109.0448","created_at":"2026-05-18T03:23:21.451296+00:00"},{"alias_kind":"arxiv_version","alias_value":"1109.0448v2","created_at":"2026-05-18T03:23:21.451296+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1109.0448","created_at":"2026-05-18T03:23:21.451296+00:00"},{"alias_kind":"pith_short_12","alias_value":"QLDNPR7572FQ","created_at":"2026-05-18T12:26:39.201973+00:00"},{"alias_kind":"pith_short_16","alias_value":"QLDNPR7572FQYCI3","created_at":"2026-05-18T12:26:39.201973+00:00"},{"alias_kind":"pith_short_8","alias_value":"QLDNPR75","created_at":"2026-05-18T12:26:39.201973+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH","json":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH.json","graph_json":"https://pith.science/api/pith-number/QLDNPR7572FQYCI3NZVJDTOCDH/graph.json","events_json":"https://pith.science/api/pith-number/QLDNPR7572FQYCI3NZVJDTOCDH/events.json","paper":"https://pith.science/paper/QLDNPR75"},"agent_actions":{"view_html":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH","download_json":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH.json","view_paper":"https://pith.science/paper/QLDNPR75","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1109.0448&json=true","fetch_graph":"https://pith.science/api/pith-number/QLDNPR7572FQYCI3NZVJDTOCDH/graph.json","fetch_events":"https://pith.science/api/pith-number/QLDNPR7572FQYCI3NZVJDTOCDH/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH/action/timestamp_anchor","attest_storage":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH/action/storage_attestation","attest_author":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH/action/author_attestation","sign_citation":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH/action/citation_signature","submit_replication":"https://pith.science/pith/QLDNPR7572FQYCI3NZVJDTOCDH/action/replication_record"}},"created_at":"2026-05-18T03:23:21.451296+00:00","updated_at":"2026-05-18T03:23:21.451296+00:00"}