{"paper":{"title":"Jacobson's thermodynamic approach to classical gravity applied to non-Riemannian geometries: remarks on the simplicity of Nature","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Jacobson's thermodynamic approach selects Einstein-Hilbert action plus quadratic torsion term for non-Riemannian geometries without non-metricity.","cross_cats":[],"primary_cat":"gr-qc","authors_text":"2) ((1) Universidad Industrial de Santander, (2) Universidad Antonio Narino), Jhan N. Martinez (1), Jose F. Rodriguez-Ruiz (2), Yeinzon Rodriguez (1","submitted_at":"2026-01-31T00:19:38Z","abstract_excerpt":"Three decades ago, Ted Jacobson surprised us with a very appealing approach to classical gravity. According to him, the gravitational field equations are the consequence of the first law of thermodynamics applied to a Rindler observer. Jacobson's approach being formulated for Riemannian geometries, we have wondered what its consequences would be for non-Riemannian geometries. The results of our quest have been particularly appealing: we have found that the theory that derives from the Einstein-Hilbert action, arguably ``the simplest one'', does not belong to the pool of gravitational theories "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Together, the two approaches point towards the theory that derives from the Einstein-Hilbert action plus a term quadratic in the torsion vector as the one that would be selected by Nature in the non-Riemannian case without non metricity (when the energy-momentum tensor is identified as its metric version).","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The hypotheses employed in the formulation of the Lanczos-Lovelock theories of gravity can be applied to the non-Riemannian case, and the thermodynamic and Lanczos-Lovelock approaches remain consistent only for specific identifications of the energy-momentum tensor and absence of non-metricity.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Jacobson's thermodynamic approach applied to non-Riemannian geometries selects the Einstein-Hilbert action plus a quadratic torsion term as Nature's choice when non-metricity is absent and the metric energy-momentum tensor is used.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Jacobson's thermodynamic approach selects Einstein-Hilbert action plus quadratic torsion term for non-Riemannian geometries without non-metricity.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"f038a4822fb2d47e4b47e0e009024a4ecbb19827076d09526558bbd5a0394577"},"source":{"id":"2602.00422","kind":"arxiv","version":3},"verdict":{"id":"a03dcf8d-3994-4f0b-9309-b68cf011c3ab","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T09:30:34.512720Z","strongest_claim":"Together, the two approaches point towards the theory that derives from the Einstein-Hilbert action plus a term quadratic in the torsion vector as the one that would be selected by Nature in the non-Riemannian case without non metricity (when the energy-momentum tensor is identified as its metric version).","one_line_summary":"Jacobson's thermodynamic approach applied to non-Riemannian geometries selects the Einstein-Hilbert action plus a quadratic torsion term as Nature's choice when non-metricity is absent and the metric energy-momentum tensor is used.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The hypotheses employed in the formulation of the Lanczos-Lovelock theories of gravity can be applied to the non-Riemannian case, and the thermodynamic and Lanczos-Lovelock approaches remain consistent only for specific identifications of the energy-momentum tensor and absence of non-metricity.","pith_extraction_headline":"Jacobson's thermodynamic approach selects Einstein-Hilbert action plus quadratic torsion term for non-Riemannian geometries without non-metricity."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2602.00422/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":2,"snapshot_sha256":"15682a026881235ff381ecd03f4741e0353430bdd572441a701dc6c16a6d5cfb"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}