{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:IXUYRHK7IDV2627PCRZIV4JXTK","short_pith_number":"pith:IXUYRHK7","canonical_record":{"source":{"id":"2606.03490","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2026-06-02T11:07:33Z","cross_cats_sorted":[],"title_canon_sha256":"0eb799e6c092d75e390cab70138d24baa8dfb345af7dbba40ef8ca94a6dacc8e","abstract_canon_sha256":"8474adc9ab28023c5414c5197c7eff0d38d0c5fa9f53b41c6714ecb96ac99c57"},"schema_version":"1.0"},"canonical_sha256":"45e9889d5f40ebaf6bef14728af1379ab4ab294960f20a46b849584b875df4b0","source":{"kind":"arxiv","id":"2606.03490","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.03490","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"arxiv_version","alias_value":"2606.03490v1","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.03490","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_12","alias_value":"IXUYRHK7IDV2","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_16","alias_value":"IXUYRHK7IDV2627P","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_8","alias_value":"IXUYRHK7","created_at":"2026-06-03T01:05:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:IXUYRHK7IDV2627PCRZIV4JXTK","target":"record","payload":{"canonical_record":{"source":{"id":"2606.03490","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2026-06-02T11:07:33Z","cross_cats_sorted":[],"title_canon_sha256":"0eb799e6c092d75e390cab70138d24baa8dfb345af7dbba40ef8ca94a6dacc8e","abstract_canon_sha256":"8474adc9ab28023c5414c5197c7eff0d38d0c5fa9f53b41c6714ecb96ac99c57"},"schema_version":"1.0"},"canonical_sha256":"45e9889d5f40ebaf6bef14728af1379ab4ab294960f20a46b849584b875df4b0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-03T01:05:59.143525Z","signature_b64":"z3adOyTd4RocxkVwyVkvFCXrlIAArYSFI0TT0vZB1aVbUNIDJ1grLTTtoQXOfbA9IEVyeVq0Pq3fDgfDn5h6CQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"45e9889d5f40ebaf6bef14728af1379ab4ab294960f20a46b849584b875df4b0","last_reissued_at":"2026-06-03T01:05:59.143129Z","signature_status":"signed_v1","first_computed_at":"2026-06-03T01:05:59.143129Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2606.03490","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":"2026-06-03T01:05:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"DxbefaqZBBtBLj5KDvovIpl6Ja9iwyNRsZ60314eqYDAPEFG1udcpo4aMtxiet65on+I9gbfPK9cZaTPy0f4DQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-29T19:57:56.681801Z"},"content_sha256":"ae7612eaacb3e31b1c8e7d91aebd249656f23cb7b9adfba47362d025345421c4","schema_version":"1.0","event_id":"sha256:ae7612eaacb3e31b1c8e7d91aebd249656f23cb7b9adfba47362d025345421c4"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:IXUYRHK7IDV2627PCRZIV4JXTK","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"TrAction: Action Recognition with Sparse Trajectories","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.CV","authors_text":"Alexander Ecker, Felix B. Mueller, Jan F. Meier, Timo L\\\"uddecke","submitted_at":"2026-06-02T11:07:33Z","abstract_excerpt":"Modern action recognition models operate on memory- and compute-intensive dense RGB video volumes and frequently exploit appearance and background shortcuts, for example, predicting actions from objects or scenes instead of characteristic motion. We investigate an efficient alternative input modality that is largely free of such biases by construction: sparse point trajectories. To this end, we develop a simple transformer architecture for 2.5D trajectory-based recognition together with a masked-trajectory pretraining, which we show to substantially improve downstream action recognition accura"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.03490","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/2606.03490/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":"2026-06-03T01:05:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QM9zo1VQVDoe23a24yYksocbAsXnnds8K/tUsAxJCBHoMa/ouCznv964ePRfm3xqZdr3GDs5zqj3fqYQHdMZCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-29T19:57:56.682164Z"},"content_sha256":"17f1b804e7e60155419ddf8df33e203215c1fde27a9c3c53a57402c9b948ae73","schema_version":"1.0","event_id":"sha256:17f1b804e7e60155419ddf8df33e203215c1fde27a9c3c53a57402c9b948ae73"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IXUYRHK7IDV2627PCRZIV4JXTK/bundle.json","state_url":"https://pith.science/pith/IXUYRHK7IDV2627PCRZIV4JXTK/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IXUYRHK7IDV2627PCRZIV4JXTK/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":"2026-06-29T19:57:56Z","links":{"resolver":"https://pith.science/pith/IXUYRHK7IDV2627PCRZIV4JXTK","bundle":"https://pith.science/pith/IXUYRHK7IDV2627PCRZIV4JXTK/bundle.json","state":"https://pith.science/pith/IXUYRHK7IDV2627PCRZIV4JXTK/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IXUYRHK7IDV2627PCRZIV4JXTK/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:IXUYRHK7IDV2627PCRZIV4JXTK","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":"8474adc9ab28023c5414c5197c7eff0d38d0c5fa9f53b41c6714ecb96ac99c57","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2026-06-02T11:07:33Z","title_canon_sha256":"0eb799e6c092d75e390cab70138d24baa8dfb345af7dbba40ef8ca94a6dacc8e"},"schema_version":"1.0","source":{"id":"2606.03490","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.03490","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"arxiv_version","alias_value":"2606.03490v1","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.03490","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_12","alias_value":"IXUYRHK7IDV2","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_16","alias_value":"IXUYRHK7IDV2627P","created_at":"2026-06-03T01:05:59Z"},{"alias_kind":"pith_short_8","alias_value":"IXUYRHK7","created_at":"2026-06-03T01:05:59Z"}],"graph_snapshots":[{"event_id":"sha256:17f1b804e7e60155419ddf8df33e203215c1fde27a9c3c53a57402c9b948ae73","target":"graph","created_at":"2026-06-03T01:05:59Z","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/2606.03490/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Modern action recognition models operate on memory- and compute-intensive dense RGB video volumes and frequently exploit appearance and background shortcuts, for example, predicting actions from objects or scenes instead of characteristic motion. We investigate an efficient alternative input modality that is largely free of such biases by construction: sparse point trajectories. To this end, we develop a simple transformer architecture for 2.5D trajectory-based recognition together with a masked-trajectory pretraining, which we show to substantially improve downstream action recognition accura","authors_text":"Alexander Ecker, Felix B. Mueller, Jan F. Meier, Timo L\\\"uddecke","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2026-06-02T11:07:33Z","title":"TrAction: Action Recognition with Sparse Trajectories"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.03490","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:ae7612eaacb3e31b1c8e7d91aebd249656f23cb7b9adfba47362d025345421c4","target":"record","created_at":"2026-06-03T01:05:59Z","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":"8474adc9ab28023c5414c5197c7eff0d38d0c5fa9f53b41c6714ecb96ac99c57","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2026-06-02T11:07:33Z","title_canon_sha256":"0eb799e6c092d75e390cab70138d24baa8dfb345af7dbba40ef8ca94a6dacc8e"},"schema_version":"1.0","source":{"id":"2606.03490","kind":"arxiv","version":1}},"canonical_sha256":"45e9889d5f40ebaf6bef14728af1379ab4ab294960f20a46b849584b875df4b0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"45e9889d5f40ebaf6bef14728af1379ab4ab294960f20a46b849584b875df4b0","first_computed_at":"2026-06-03T01:05:59.143129Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-03T01:05:59.143129Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"z3adOyTd4RocxkVwyVkvFCXrlIAArYSFI0TT0vZB1aVbUNIDJ1grLTTtoQXOfbA9IEVyeVq0Pq3fDgfDn5h6CQ==","signature_status":"signed_v1","signed_at":"2026-06-03T01:05:59.143525Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.03490","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ae7612eaacb3e31b1c8e7d91aebd249656f23cb7b9adfba47362d025345421c4","sha256:17f1b804e7e60155419ddf8df33e203215c1fde27a9c3c53a57402c9b948ae73"],"state_sha256":"06930c440ab9c96cc2fac89b5ae4d88816dc3a8519c91321a25d77dd3b9fe197"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ch/zdg8RPruKIZVr3ie258nCnGlSN4QHcw34HXDnfF4hCneH9A/8lIbxr1t9rPf/3E/SWVVXr/A6zQvyLLedCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-29T19:57:56.684070Z","bundle_sha256":"58aafa6e6d2574367c10d6f2e245484632a63324cb9a7d9d992315ec20170635"}}