The generalized second law of gravitational thermodynamics on the apparent and event horizons in FRW cosmology

TL;DR

This paper examines the validity of the generalized second law of gravitational thermodynamics on apparent and event horizons in a non-flat FRW universe with interacting dark energy and dark matter, finding it always holds on the apparent horizon but depends on the equation of state on the event horizon.

Contribution

It demonstrates the universal validity of the generalized second law on the apparent horizon regardless of spatial curvature or dark energy properties.

Findings

The law always holds on the apparent horizon.

On the event horizon, validity depends on the dark energy equation of state.

The results are independent of the universe's spatial curvature.

Abstract

We investigate the validity of the generalized second law of gravitational thermodynamics on the apparent and event horizons in a non-flat FRW universe containing the interacting dark energy with dark matter. We show that for the dynamical apparent horizon, the generalized second law is always satisfied throughout the history of the universe for any spatial curvature and it is independent of the equation of state parameter of the interacting dark energy model. Whereas for the cosmological event horizon, the validity of the generalized second law depends on the equation of state parameter of the model.