{"paper":{"title":"Testing the 3-equation Kuhfuss Convection Model using the Sun","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"The 3-equation Kuhfuss model produces a more realistic temperature gradient at the base of the Sun's convective envelope.","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"A. Weiss, F. Ahlborn, F. Kupka, T. A. M. Braun","submitted_at":"2026-04-07T17:52:32Z","abstract_excerpt":"Simplified, one-dimensional models are necessary to model convection in the context of stellar evolution. By including the non-local effects of convection, turbulent convection models describe convection in a more physical way compared to mixing length theory, which is typically used in one-dimensional stellar evolution models. We recently showed that the 1-equation Kuhfuss turbulent convection model is not sufficient to model the solar convective envelope satisfactorily. Using the Sun as a benchmark, we test the physically more complete 3-equation Kuhfuss turbulent convection model. We calcul"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We find that, with the 3-equation model, the temperature gradient at the inner boundary of the convective envelope is modelled more realistically compared to the mixing length theory or the 1-equation model. This also improves the agreement for the sound speed profile between the model and the Sun, and reduces the asteroseismic surface effect.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the closure relations of the 3-equation Kuhfuss model remain valid throughout the solar convective envelope even though they produce an unphysical negative temperature gradient near the surface.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"The 3-equation Kuhfuss model improves solar interior structure predictions over mixing-length theory and the 1-equation version but produces an unphysical negative temperature gradient near the surface due to its closure relations.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"The 3-equation Kuhfuss model produces a more realistic temperature gradient at the base of the Sun's convective envelope.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"28758718bb1076f6004857cda1d93fff6a6edeb6d86e0a794fae29b9dfd6bec3"},"source":{"id":"2604.06151","kind":"arxiv","version":1},"verdict":{"id":"c1220e8b-d6c3-4d18-94bd-44eb11f609be","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T18:46:35.200426Z","strongest_claim":"We find that, with the 3-equation model, the temperature gradient at the inner boundary of the convective envelope is modelled more realistically compared to the mixing length theory or the 1-equation model. This also improves the agreement for the sound speed profile between the model and the Sun, and reduces the asteroseismic surface effect.","one_line_summary":"The 3-equation Kuhfuss model improves solar interior structure predictions over mixing-length theory and the 1-equation version but produces an unphysical negative temperature gradient near the surface due to its closure relations.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the closure relations of the 3-equation Kuhfuss model remain valid throughout the solar convective envelope even though they produce an unphysical negative temperature gradient near the surface.","pith_extraction_headline":"The 3-equation Kuhfuss model produces a more realistic temperature gradient at the base of the Sun's convective envelope."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.06151/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":3,"sample":[{"doi":"10.1051/0004-","year":2026,"title":"Third order correlations and skewness in convection. I. A new approach suitable for three-equation non-local models","work_id":"d9716c24-9d51-4133-85d3-ba33776ce902","ref_index":1,"cited_arxiv_id":"2603.00832","is_internal_anchor":true},{"doi":"","year":2022,"title":"(2022) (Asplund et al","work_id":"9af66428-9570-4d49-acb7-61f2d533ec0c","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2009,"title":"Article number, page 14 of 15 T. A. M. Braun et al.: Testing the 3-equation Kuhfuss Convection Model using the Sun Table B.1.Testing the effect of using the abundances from Asplund et al. (2009) (Appe","work_id":"e5d3f670-a93f-4d50-be8e-8f9bf7b1c39d","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":3,"snapshot_sha256":"8f38b6b3fbe398e35a065769fde3de8a4b6748c8f4ada03c4c9c0a1f7c203e9e","internal_anchors":1},"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"}