Bouncing cosmological models in $f(R,L_m)$ gravity

TL;DR

This paper investigates non-singular bouncing cosmological models within $f(R,L_m)$ gravity, analyzing their dynamics, energy conditions, and viability through various parameters and functions.

Contribution

It introduces two specific non-linear $f(R,L_m)$ models and derives their cosmological equations, exploring conditions for non-singular bouncing behavior and stability.

Findings

Null energy condition violation enables non-singular acceleration.

Model parameters influence the equation of state and cosmographic parameters.

Speed of sound analysis supports model viability.

Abstract

This article explores matter bounce non-singular cosmology in $f(R,L_m)$ gravity. We consider two non-linear $f(R,L_m)$ functional forms, specifically, $f(R,L_m) = \frac{R}{2} + \lambda R^2 + \alpha L_m$ and $f(R,L_m) = \frac{R}{2} + L_m ^\beta + \gamma$ representing a minimal coupling case. We derive the corresponding Friedmann-like equations for both the assumed models in the FLRW background, and then we present the impact of the model parameters along with the parameter of bouncing scale factor on the equation of state parameter, pressure, and the energy density. In addition, we examine the dynamical behavior of cosmographic parameters such as jerk, lerk, and snap parameters. Further, we find that the violation of the null energy condition along with the strong energy condition depicts the non-singular accelerating behavior, corresponding to both assumed non-linear $f(R,L_m)$ functions. Lastly, we present the behavior of the adiabatic speed of sound to examine the viability of the considered cosmological bouncing scenario.