Non-singular Bouncing Cosmology in $f(R,G,T)$--Quintom model

Farzad Milani

doi:10.1088/1475-7516/2026/08/083

paper

Non-singular Bouncing Cosmology in $f (R, G, T)$ --Quintom model

arXiv:2510.00688 · doi:10.1088/1475-7516/2026/08/083

Abstract

We present a unified framework for non-singular bouncing cosmologies in modified gravity, combining $f (R, G, T)$ geometry with quintom scalar dynamics in a flat FLRW universe. While single-field models achieve phantom divide line (PDL) crossing and stable bounces, our $f (R, G, T)$ -quintom coupling provides a novel implementation of a \textit{double} PDL crossing of $ω_{eff}$ during the bounce. We address stability concerns through Hamiltonian analysis, showing that FLRW symmetry constraints suppress Ostrogradsky instabilities by reducing higher-derivative terms to metric invariant. The scalar field equation of motion is explicitly derived, confirming cancellation of pathological modes. Numerical reconstruction of five $f (R, G, T)$ models confirms non-singular bounces with $ρ_{eff} > 0$ and $c_{s}^{2} \geq 0$ , alongside parametric control over energy condition violations. Our work extends prior studies by: (1) unifying early-time bounce dynamics with late-time dark energy, (2) demonstrating a novel double-PDL crossing signature compatible with FLRW stability, and (3) establishing explicit ghost-free criteria for higher-derivative terms.

77 pages, 42 figures, 8 appendices, 68 references, 1 table

Non-singular Bouncing Cosmology in f(R,G,T)--Quintom model

Abstract

References in corpus (51)

Non-singular Bouncing Cosmology in $f (R, G, T)$ --Quintom model