2024/07/01 by Ayush Hazarika, Simran Arora, Hazarika, Ayush +5 · 3 citations
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2407.00989
openalex publication_date 2024/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Symmetric teleparallel gravity and its f(Q) extensions have emerged as promising alternatives to General Relativity (GR), yet the role of explicit geometry-matter couplings remains largely unexplored. In this work, we address this gap by proposing a generalized f(Q,Lm) theory, where the gravitational Lagrangian density depends on both the non-metricity scalar Q and the matter Lagrangian Lm. This formulation naturally includes Coincident GR and the Symmetric Teleparallel Equivalent of GR as special cases. Working in the metric formalism, we derive the corresponding field equations, which generalize those of the standard f(Q) gravity, and obtain the modified Klein-Gordon equation for scenarios involving scalar fields. The cosmological implications of the theory are explored in the context of the Friedmann-Lemaitre-Robertson-Walker (FLRW) universe. As a first step, we obtain the modified Friedmann equations for f(Q,Lm) gravity in full generality. We then investigate specific cosmological models arising from both linear and non-linear choices of f(Q,Lm), performing detailed comparisons with the standard ΛCDM scenario and examining their observational consequences.