Universal thermodynamics in different gravity theories: Conditions for generalized second law of thermodynamics and thermodynamical equilibrium on the horizons

TL;DR

This paper investigates the validity of the generalized second law of thermodynamics and thermodynamical equilibrium on horizons within various modified gravity theories, using observational data and corrected thermodynamical parameters.

Contribution

It provides a comprehensive analysis of thermodynamics in different gravity theories with corrected entropy and temperature, including observational constraints and graphical validation.

Findings

GSLT and TE conditions vary across gravity models.

Corrected entropy and temperature influence thermodynamical laws.

Graphical analysis supports theoretical restrictions.

Abstract

The present work deals with a detailed study of universal thermodynamics in different modified gravity theories. The validity of the generalized second law of thermodynamics (GSLT) and thermodynamical equilibrium (TE) of the Universe bounded by a horizon (apparent/event) in f(R)-gravity, Einstein-Gauss-Bonnet gravity, RS-II brane scenario and DGP brane model has been investigated. In the perspective of recent observational evidences, the matter in the Universe is chosen as interacting holographic dark energy model. The entropy on the horizons are evaluated from the validity of the unified first law and as a result there is a correction (in integral form) to the usual Bekenstein entropy. The other thermodynamical parameter namely temperature on the horizon is chosen as the recently introduced corrected Hawking temperature. The above thermodynamical analysis is done for homogeneous and isotropic flat FLRW model of the Universe. The restrictions for the validity of GSLT and the TE are presented in tabular form for each gravity theory. Finally, due to complicated expressions, the validity of GSLT and TE are also examined from graphical representation, using three Planck data sets.