{"paper":{"title":"Homothetic Killing horizons in generic Vaidya spacetimes","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Vaidya spacetimes admit unique homothetic Killing vectors when mass, charge or spin parameters vary linearly with advanced time.","cross_cats":["hep-th"],"primary_cat":"gr-qc","authors_text":"Nilay Kundu, Ritwika Ghoshal, Srijit Bhattacharjee","submitted_at":"2026-04-10T17:26:41Z","abstract_excerpt":"We study the conformal Killing equation for generic Vaidya-like spacetimes, including those with rotation. We show that these spacetimes admit a unique class of conformal Killing vectors that are homothetic for mass, charge, or rotation parameters being linear functions of the advanced null-time. For the Kerr-Vaidya metric, the solution to the conformal Killing equation exists iff both mass and rotation parameters become dynamic. The presence of a homothetic Killing vector (HKV) for such a spacetime enables one to conformally map the original dynamical spacetime to a stationary spacetime, enab"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We show that these spacetimes admit a unique class of conformal Killing vectors that are homothetic for mass, charge, or rotation parameters being linear functions of the advanced null-time.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that the mass, charge, or rotation parameters are linear functions of the advanced null-time, which is required for the homothetic property to hold and for the conformal mapping to work.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Generic Vaidya spacetimes with linear time-dependent mass, charge or rotation admit unique homothetic Killing vectors, allowing conformal mapping to stationary metrics and thermodynamic analysis of homothetic Killing horizons.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Vaidya spacetimes admit unique homothetic Killing vectors when mass, charge or spin parameters vary linearly with advanced time.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"a3bd8a720a11022540ebb1eee73188d7851d539509adee0b09809da2560f0248"},"source":{"id":"2604.09760","kind":"arxiv","version":2},"verdict":{"id":"d17bc3f6-9144-4d03-925a-67ba4a9afa87","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T17:07:59.804744Z","strongest_claim":"We show that these spacetimes admit a unique class of conformal Killing vectors that are homothetic for mass, charge, or rotation parameters being linear functions of the advanced null-time.","one_line_summary":"Generic Vaidya spacetimes with linear time-dependent mass, charge or rotation admit unique homothetic Killing vectors, allowing conformal mapping to stationary metrics and thermodynamic analysis of homothetic Killing horizons.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that the mass, charge, or rotation parameters are linear functions of the advanced null-time, which is required for the homothetic property to hold and for the conformal mapping to work.","pith_extraction_headline":"Vaidya spacetimes admit unique homothetic Killing vectors when mass, charge or spin parameters vary linearly with advanced time."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.09760/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"}