English

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

General Relativity and Quantum Cosmology 2025-03-27 v1

Abstract

In this study, we explore the dynamics of the universe using a modified gravity model represented by f(R,G,T)f(R, G, T), where RR is the Ricci scalar, GG is the Gauss-Bonnet invariant, and TT is the trace of the stress-energy tensor. The model incorporates two scalar fields and is analyzed within a flat Friedmann-Lema\^{\i}tre-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=0t = 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)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.

Keywords

Cite

@article{arxiv.2503.20709,
  title  = {Bouncing Theory in the Modified $f(R,G,T)$ Gravity},
  author = {Farzad Milani},
  journal= {arXiv preprint arXiv:2503.20709},
  year   = {2025}
}

Comments

45 pages, 32 figures

R2 v1 2026-06-28T22:35:26.761Z