{"paper":{"title":"Dynamical and Observational Analysis of Generalized Nash's Theory of Gravity","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"Amin Rezaei Akbarieh, Mohammad Amin Bolouri, Yaghoub Heydarzade","submitted_at":"2026-07-24T09:20:02Z","abstract_excerpt":"We investigate cosmic evolution in generalized Nash's theory of gravity involving the quadratic Ricci invariant $\\chi=R_{\\mu\\nu}R^{\\mu\\nu}$. The analysis is divided into two complementary branches. First, we study the power-law family $f(R,\\chi)=R^{\\alpha}+\\beta\\chi$ as a reduced autonomous system in a flat FLRW background. Because the adopted variables become singular at the Einstein--Hilbert limit $\\alpha=1$, the phase-space analysis is restricted to $\\alpha\\neq1$, with $\\alpha=2$ used as a representative quadratic benchmark. This benchmark contains radiation-like boundary configurations, re"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.22126","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/2607.22126/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"}