{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2007:CJMXKXJWUBMSVN63XZKFUFIMMC","short_pith_number":"pith:CJMXKXJW","schema_version":"1.0","canonical_sha256":"1259755d36a0592ab7dbbe545a150c608d6fa5d994918bbb06890e0cd6257865","source":{"kind":"arxiv","id":"0712.3779","version":3},"attestation_state":"computed","paper":{"title":"Non-Gaussian Density Fluctuations from Entropically Generated Curvature Perturbations in Ekpyrotic Models","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph"],"primary_cat":"hep-th","authors_text":"Jean-Luc Lehners, Paul J. Steinhardt","submitted_at":"2007-12-21T19:27:00Z","abstract_excerpt":"We analyze the non-gaussian density perturbations generated in ekpyrotic/cyclic models based on heterotic M-theory. In this picture, two scalar fields produce nearly scale-invariant entropic perturbations during an ekpyrotic phase that are converted into curvature modes {\\it after the ekpyrotic phase is complete} and just before the big bang. Both intrinsic non-linearity in the entropy perturbation and the conversion process contribute to non-gaussianity. The range of the non-gaussianity parameter $f_{NL}$ depends on how gradual the conversion process is and the steepness of the scalar field p"},"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":"0712.3779","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-th","submitted_at":"2007-12-21T19:27:00Z","cross_cats_sorted":["astro-ph"],"title_canon_sha256":"cd53d825166fd78442b18d87960067e5024036180ffddf161bac121c78edb222","abstract_canon_sha256":"9d071f28faeb808d489bc890e486b6428c7684e92fcdb6bfde25a49db0e756ba"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:35:23.929791Z","signature_b64":"zIrcVcvMbTqN48mCBepwlw16aYUz9jTUzhJUAt1LOVIcfpgS5Fh6UL08lIbiIlc2xtDpj/a36vTzBs5HJitTBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1259755d36a0592ab7dbbe545a150c608d6fa5d994918bbb06890e0cd6257865","last_reissued_at":"2026-05-18T02:35:23.929340Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:35:23.929340Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Non-Gaussian Density Fluctuations from Entropically Generated Curvature Perturbations in Ekpyrotic Models","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph"],"primary_cat":"hep-th","authors_text":"Jean-Luc Lehners, Paul J. Steinhardt","submitted_at":"2007-12-21T19:27:00Z","abstract_excerpt":"We analyze the non-gaussian density perturbations generated in ekpyrotic/cyclic models based on heterotic M-theory. In this picture, two scalar fields produce nearly scale-invariant entropic perturbations during an ekpyrotic phase that are converted into curvature modes {\\it after the ekpyrotic phase is complete} and just before the big bang. Both intrinsic non-linearity in the entropy perturbation and the conversion process contribute to non-gaussianity. The range of the non-gaussianity parameter $f_{NL}$ depends on how gradual the conversion process is and the steepness of the scalar field p"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0712.3779","kind":"arxiv","version":3},"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":"0712.3779","created_at":"2026-05-18T02:35:23.929406+00:00"},{"alias_kind":"arxiv_version","alias_value":"0712.3779v3","created_at":"2026-05-18T02:35:23.929406+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0712.3779","created_at":"2026-05-18T02:35:23.929406+00:00"},{"alias_kind":"pith_short_12","alias_value":"CJMXKXJWUBMS","created_at":"2026-05-18T12:25:55.427421+00:00"},{"alias_kind":"pith_short_16","alias_value":"CJMXKXJWUBMSVN63","created_at":"2026-05-18T12:25:55.427421+00:00"},{"alias_kind":"pith_short_8","alias_value":"CJMXKXJW","created_at":"2026-05-18T12:25:55.427421+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":2,"internal_anchor_count":2,"sample":[{"citing_arxiv_id":"2605.12579","citing_title":"Phase-resolved field-space distance bounds in ekpyrotic, bouncing and cyclic cosmologies","ref_index":77,"is_internal_anchor":true},{"citing_arxiv_id":"2605.12579","citing_title":"Phase-resolved field-space distance bounds in ekpyrotic, bouncing and cyclic cosmologies","ref_index":70,"is_internal_anchor":true}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC","json":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC.json","graph_json":"https://pith.science/api/pith-number/CJMXKXJWUBMSVN63XZKFUFIMMC/graph.json","events_json":"https://pith.science/api/pith-number/CJMXKXJWUBMSVN63XZKFUFIMMC/events.json","paper":"https://pith.science/paper/CJMXKXJW"},"agent_actions":{"view_html":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC","download_json":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC.json","view_paper":"https://pith.science/paper/CJMXKXJW","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0712.3779&json=true","fetch_graph":"https://pith.science/api/pith-number/CJMXKXJWUBMSVN63XZKFUFIMMC/graph.json","fetch_events":"https://pith.science/api/pith-number/CJMXKXJWUBMSVN63XZKFUFIMMC/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC/action/timestamp_anchor","attest_storage":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC/action/storage_attestation","attest_author":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC/action/author_attestation","sign_citation":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC/action/citation_signature","submit_replication":"https://pith.science/pith/CJMXKXJWUBMSVN63XZKFUFIMMC/action/replication_record"}},"created_at":"2026-05-18T02:35:23.929406+00:00","updated_at":"2026-05-18T02:35:23.929406+00:00"}