Generalized Chaplygin gas and accelerating universe in $f(Q,T)$ gravity

TL;DR

This paper explores a modified gravity model, $f(Q,T)$ gravity, coupled with generalized Chaplygin gas to explain the universe's accelerated expansion, fitting observational data and analyzing dark energy characteristics.

Contribution

It introduces new functional forms of $f(Q,T)$ gravity with GCG and tests their viability against observational data, highlighting their role in cosmic acceleration.

Findings

Models predict transition from deceleration to acceleration.

Equation of state becomes negative, indicating acceleration.

Statefinder analysis differentiates these models from others.

Abstract

The generalized Chaplygin gas (GCG), which has an unusual perfect fluid equation of state, is another promising candidate for dark energy. We investigate the GCG scenario coupled with a baryonic matter in a newly suggested $f(Q,T)$ gravity, an arbitrary function of non-metricity $Q$ and the trace of energy-momentum tensor $T$. We consider the functional form of $f(Q, T)$ as a linear combination of $Q$ and an arbitrary function of $T$, denoted by $h(T)$. Furthermore, we obtain two different functional forms of the $f(Q,T)$ model under high pressure and high-density scenarios of GCG. We also test each model with the recent Pantheon supernovae data set of 1048 data points, Hubble data set of 31 points, and baryon acoustic oscillations. The deceleration parameter is constructed using $OHD+SNeIa+BAO$, predicting a transition from decelerated to accelerated phases of the universe expansion. Also, the equation of state parameter acquires a negative behavior depicting acceleration. Finally, we analyze the statefinder diagnostic to discriminate between the GCG and other dark energy models.