{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:WAJUT6FFWVP4TKAFCE4YAM4LYC","short_pith_number":"pith:WAJUT6FF","canonical_record":{"source":{"id":"2606.30037","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-29T09:35:21Z","cross_cats_sorted":["q-fin.RM","q-fin.ST"],"title_canon_sha256":"6d22e18619f498caa3b6afd879556f453e1fc9d90312d480c926445aa9e156ab","abstract_canon_sha256":"2a9e665c029239b8ea20290b13c438054a4e06d63fec77edc10b605bbe1c4bb0"},"schema_version":"1.0"},"canonical_sha256":"b01349f8a5b55fc9a805113980338bc0855c50e684b0867610172becfdc29ab6","source":{"kind":"arxiv","id":"2606.30037","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.30037","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"arxiv_version","alias_value":"2606.30037v1","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.30037","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_12","alias_value":"WAJUT6FFWVP4","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_16","alias_value":"WAJUT6FFWVP4TKAF","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_8","alias_value":"WAJUT6FF","created_at":"2026-06-30T02:17:47Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:WAJUT6FFWVP4TKAFCE4YAM4LYC","target":"record","payload":{"canonical_record":{"source":{"id":"2606.30037","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-29T09:35:21Z","cross_cats_sorted":["q-fin.RM","q-fin.ST"],"title_canon_sha256":"6d22e18619f498caa3b6afd879556f453e1fc9d90312d480c926445aa9e156ab","abstract_canon_sha256":"2a9e665c029239b8ea20290b13c438054a4e06d63fec77edc10b605bbe1c4bb0"},"schema_version":"1.0"},"canonical_sha256":"b01349f8a5b55fc9a805113980338bc0855c50e684b0867610172becfdc29ab6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-30T02:17:47.063461Z","signature_b64":"5ZZwB0lul8BirwavjB95DbSbd0Lp0P3k/JHTLH/DJitlxHBpZBRAuzbBLHpLLQOuwTnQTYtfN0nZWNuAmam/Cw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b01349f8a5b55fc9a805113980338bc0855c50e684b0867610172becfdc29ab6","last_reissued_at":"2026-06-30T02:17:47.062949Z","signature_status":"signed_v1","first_computed_at":"2026-06-30T02:17:47.062949Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2606.30037","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":"2026-06-30T02:17:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"trPVIavFgTW/eVjyquv+PBcSi6izaaRZiTY/kEg1Q7Ur4K4Vzp+JcWRoBCGiTkyiZe0AZRL35O+HF+kpEO7qDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T07:39:49.215400Z"},"content_sha256":"7e42183c10f7236ab066c46aa7b704d0355a3d5eab5901da90f4f47079fe1d30","schema_version":"1.0","event_id":"sha256:7e42183c10f7236ab066c46aa7b704d0355a3d5eab5901da90f4f47079fe1d30"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:WAJUT6FFWVP4TKAFCE4YAM4LYC","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Heads, Not Backbones: Output Heads Dominate Architectures on Fat-Tailed Returns","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["q-fin.RM","q-fin.ST"],"primary_cat":"cs.LG","authors_text":"Sichao He, Yansong Zhang","submitted_at":"2026-06-29T09:35:21Z","abstract_excerpt":"In a deep forecasting pipeline for fat-tailed financial returns at short horizons, which matters more - the backbone architecture or the output head? We compare four modern backbones (TimesNet, DLinear, N-BEATS, iTransformer) under three output heads: a point head, a single-Gaussian density head, and a Gaussian mixture density head with K=4 components. On S and P 500 monthly log-returns (1871-2023) under anchored walk-forward validation, the three heads form a strict gradient: switching from point to Gaussian improves CRPS by about 1.3 percent; switching from Gaussian to mixture adds a further"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.30037","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.30037/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-06-30T02:17:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WimHodTKAf8TzFD6ozvueNKniWjLL5q0O6J2vwSVVd3rMC0kPkR5xB7HF4ppaVbeuwAXxmWB4zaj6HiLlfCQAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T07:39:49.215774Z"},"content_sha256":"db22f41ef33d40f89ef03e40950d2778f5a82602170ae77ed4d6f6972b77bafb","schema_version":"1.0","event_id":"sha256:db22f41ef33d40f89ef03e40950d2778f5a82602170ae77ed4d6f6972b77bafb"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/bundle.json","state_url":"https://pith.science/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/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":"2026-07-05T07:39:49Z","links":{"resolver":"https://pith.science/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC","bundle":"https://pith.science/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/bundle.json","state":"https://pith.science/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/state.json","well_known_bundle":"https://pith.science/.well-known/pith/WAJUT6FFWVP4TKAFCE4YAM4LYC/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:WAJUT6FFWVP4TKAFCE4YAM4LYC","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":"2a9e665c029239b8ea20290b13c438054a4e06d63fec77edc10b605bbe1c4bb0","cross_cats_sorted":["q-fin.RM","q-fin.ST"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-29T09:35:21Z","title_canon_sha256":"6d22e18619f498caa3b6afd879556f453e1fc9d90312d480c926445aa9e156ab"},"schema_version":"1.0","source":{"id":"2606.30037","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.30037","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"arxiv_version","alias_value":"2606.30037v1","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.30037","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_12","alias_value":"WAJUT6FFWVP4","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_16","alias_value":"WAJUT6FFWVP4TKAF","created_at":"2026-06-30T02:17:47Z"},{"alias_kind":"pith_short_8","alias_value":"WAJUT6FF","created_at":"2026-06-30T02:17:47Z"}],"graph_snapshots":[{"event_id":"sha256:db22f41ef33d40f89ef03e40950d2778f5a82602170ae77ed4d6f6972b77bafb","target":"graph","created_at":"2026-06-30T02:17:47Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2606.30037/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In a deep forecasting pipeline for fat-tailed financial returns at short horizons, which matters more - the backbone architecture or the output head? We compare four modern backbones (TimesNet, DLinear, N-BEATS, iTransformer) under three output heads: a point head, a single-Gaussian density head, and a Gaussian mixture density head with K=4 components. On S and P 500 monthly log-returns (1871-2023) under anchored walk-forward validation, the three heads form a strict gradient: switching from point to Gaussian improves CRPS by about 1.3 percent; switching from Gaussian to mixture adds a further","authors_text":"Sichao He, Yansong Zhang","cross_cats":["q-fin.RM","q-fin.ST"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-29T09:35:21Z","title":"Heads, Not Backbones: Output Heads Dominate Architectures on Fat-Tailed Returns"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.30037","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":"sha256:7e42183c10f7236ab066c46aa7b704d0355a3d5eab5901da90f4f47079fe1d30","target":"record","created_at":"2026-06-30T02:17:47Z","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":"2a9e665c029239b8ea20290b13c438054a4e06d63fec77edc10b605bbe1c4bb0","cross_cats_sorted":["q-fin.RM","q-fin.ST"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-29T09:35:21Z","title_canon_sha256":"6d22e18619f498caa3b6afd879556f453e1fc9d90312d480c926445aa9e156ab"},"schema_version":"1.0","source":{"id":"2606.30037","kind":"arxiv","version":1}},"canonical_sha256":"b01349f8a5b55fc9a805113980338bc0855c50e684b0867610172becfdc29ab6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b01349f8a5b55fc9a805113980338bc0855c50e684b0867610172becfdc29ab6","first_computed_at":"2026-06-30T02:17:47.062949Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-30T02:17:47.062949Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"5ZZwB0lul8BirwavjB95DbSbd0Lp0P3k/JHTLH/DJitlxHBpZBRAuzbBLHpLLQOuwTnQTYtfN0nZWNuAmam/Cw==","signature_status":"signed_v1","signed_at":"2026-06-30T02:17:47.063461Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.30037","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7e42183c10f7236ab066c46aa7b704d0355a3d5eab5901da90f4f47079fe1d30","sha256:db22f41ef33d40f89ef03e40950d2778f5a82602170ae77ed4d6f6972b77bafb"],"state_sha256":"10a7ef35454acdb1a1995018e97f4f1904a855d9c5d69b86f6b54e3b1415f186"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"kSnI9RrekJi40CsgEWBG00/U2iCuUR85yl0wXiSb2DCJIP9fHAib1b8I5YoWJPFPZi/iJ7jO8gEuXtCHquEADw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-05T07:39:49.217726Z","bundle_sha256":"8a2fa1a0ba77a3d9dbf00580814ddc630aed08757342d697359f303f18525a2a"}}