{"paper":{"title":"Cosmology in generalized Horndeski theories with second-order equations of motion","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","gr-qc","hep-ph"],"primary_cat":"hep-th","authors_text":"Ryotaro Kase, Shinji Tsujikawa","submitted_at":"2014-07-03T06:26:46Z","abstract_excerpt":"We study the cosmology of an extended version of Horndeski theories with second-order equations of motion on the flat Friedmann-Lema\\^{i}tre-Robertson-Walker (FLRW) background. In addition to a dark energy field $\\chi$ associated with the gravitational sector, we take into account multiple scalar fields $\\phi_I$ ($I=1,2\\cdots,N-1$) characterized by the Lagrangians $P^{(I)}(X_I)$ with $X_I=\\partial_{\\mu}\\phi_I\\partial^{\\mu}\\phi_I$. These additional scalar fields can model the perfect fluids of radiation and non-relativistic matter. We derive propagation speeds of scalar and tensor perturbations"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1407.0794","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}