Bouncing Theory in the Modified $f(R,G,T)$ Gravity

Fuente: arXiv
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Autor principal: Milani, Farzad
Formato: Preprint
Publicado: 2025
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author Milani, Farzad
author_facet Milani, Farzad
contents In this study, we explore the dynamics of the universe using a modified gravity model represented by $f(R, G, T)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant, and $T$ is the trace of the stress-energy tensor. The model incorporates two scalar fields and is analyzed within a flat Friedmann-Lema\^ıtre-Robertson-Walker (FLRW) universe. We derive the equations of motion, energy-momentum tensor components, energy density, and pressure while establishing conservation laws. Using the Einstein field equations, we obtain modified Friedmann equations and simplify their solutions. We emphasize crossing the phantom divide line (PDL) of the equation of state (EoS) parameter and reversing the scale factor and Hubble parameter at $t = 0$ to resolve the singularity problem by proposing a bouncing cosmology, thereby exploring early universe dynamics without an initial singularity. By analyzing five samples $f(R, G, T)$ models, we reconstruct their effective energy density and pressure, demonstrating the significance of crossing the PDL. Our framework generalizes other theories, including conformally modified Weyl gravity, and is validated through numerical calculations and graphical results.
format Preprint
id arxiv_https___arxiv_org_abs_2503_20709
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bouncing Theory in the Modified $f(R,G,T)$ Gravity
Milani, Farzad
General Relativity and Quantum Cosmology
In this study, we explore the dynamics of the universe using a modified gravity model represented by $f(R, G, T)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant, and $T$ is the trace of the stress-energy tensor. The model incorporates two scalar fields and is analyzed within a flat Friedmann-Lema\^ıtre-Robertson-Walker (FLRW) universe. We derive the equations of motion, energy-momentum tensor components, energy density, and pressure while establishing conservation laws. Using the Einstein field equations, we obtain modified Friedmann equations and simplify their solutions. We emphasize crossing the phantom divide line (PDL) of the equation of state (EoS) parameter and reversing the scale factor and Hubble parameter at $t = 0$ to resolve the singularity problem by proposing a bouncing cosmology, thereby exploring early universe dynamics without an initial singularity. By analyzing five samples $f(R, G, T)$ models, we reconstruct their effective energy density and pressure, demonstrating the significance of crossing the PDL. Our framework generalizes other theories, including conformally modified Weyl gravity, and is validated through numerical calculations and graphical results.
title Bouncing Theory in the Modified $f(R,G,T)$ Gravity
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2503.20709