Multiple fluid theory of cosmic evolution and its thermodynamic analysis

TL;DR

This paper proposes a unified modified gravity and dark energy model incorporating thermodynamic analysis, viscous effects, and stability conditions to address multiple cosmological problems and compare with existing models.

Contribution

It introduces a novel unification of modified gravity with dark energy models, including viscous effects and stability analysis, to solve various cosmological issues.

Findings

Addressed thermodynamics energy conditions violations

Analyzed viscous effects and stability conditions

Compared state finder trajectories with other DE models

Abstract

In this paper we have discussed the modified gravity and scalar field DE model specifically DBI essence model with the analysis of thermodynamics during cosmological evolution. We have used the modified gravity with the form f(R,T)=R+2\Lambda T in our calculations. The basic aim behind this paper is to discuss a theory that unifies modified gravity with DE models including the solutions of some cosmological problems like thermodynamics energy conditions violation problems, finite time future singularity problems, initial singularity problem, Cosmic inflation problem, decelerated expansion problem, graceful exit problem, reheating problem, bouncing nature problem, phase transformation-spontaneous symmetry breaking problem, negative heat capacity paradox problem and obviously the present day universe problems (Continuously decreasing temperature problem, present day DE dominated expansion problem). We have established the viscous effects (both positive and negative viscosity) in our calculation and discussed the negative-positive viscosity by introducing two special type of energy cycles. Finally, we have discussed the stability conditions for universe evolution through cosmic perturbation and resolved the instability problems. We have also shown the state finder trajectories for both with and without viscous fluid on the basis of our calculations to compare our research with the results of other independent DE models