Particle Creation and Variable Generalized Chaplygin Gas in $\mathcal{F}(\mathcal{R},\Sigma,\mathcal{T})$ Gravity

TL;DR

This paper explores a modified gravity model with particle creation and variable Chaplygin gas, demonstrating its consistency with observations and thermodynamic stability in explaining late-time cosmic acceleration.

Contribution

It introduces a novel (\u211d,\u03a3,T) gravity framework with particle creation and variable Chaplygin gas, constrained by observational data.

Findings

Model aligns with supernova and Hubble data.

Entropy evolution remains physically consistent.

Supports late-time acceleration in a thermodynamically stable manner.

Abstract

In this work, we investigate the cosmological dynamics of a spatially flat Friedmann--Lema\^itre--Robertson--Walker Universe in the framework of generalized \( \mathcal{F}(\mathcal{R},\Sigma,\mathcal{T}) \) gravity by incorporating gravitationally induced particle creation together with the variable generalized Chaplygin gas scenario. The modified gravitational action depends explicitly on the Ricci scalar \( \mathcal{R} \), the matter-coupling scalar \( \Sigma \), and the trace of the energy--momentum tensor \( \mathcal{T} \), which collectively generate significant corrections to the standard cosmological evolution. The particle creation mechanism is introduced through an open thermodynamic description of the Universe. In addition, the dark sector is modeled using the variable generalized Chaplygin gas formalism. To examine the observational consistency of the model, the free parameters are constrained using the Pantheon\(^+\) Type Ia Supernova compilation together with the combined observational Hubble and Pantheon\(^+\) datasets through a statistical \(\chi^2\)-analysis. The cosmological behavior of the model is further explored through the evolution of the cosmological parameters. Furthermore, the thermodynamic properties of the model are investigated using the apparent horizon formalism. The obtained results demonstrate that the entropy evolution remains physically consistent throughout the cosmic evolution. Hence, the present \( \mathcal{F}(\mathcal{R},\Sigma,\mathcal{T}) \) gravity framework with particle creation provides a viable geometrical description of the late-time accelerated Universe and remains compatible with recent cosmological observations.