Gauss-Bonnet dark energy on Ho\v{r}ava-Lifshitz cosmology

TL;DR

This paper explores the effects of Gauss-Bonnet dark energy within Hořava-Lifshitz cosmology, analyzing energy transfer, thermal stability, and the generalized second law, revealing transient thermal equilibrium and sign-changing energy flux.

Contribution

It introduces a novel analysis of Gauss-Bonnet dark energy in Hořava-Lifshitz cosmology, focusing on bulk-boundary energy transfer and thermodynamic stability.

Findings

The $Q$ function can change sign during cosmic evolution.

The universe reaches thermal equilibrium transiently.

The generalized second law holds under certain conditions.

Abstract

We investigate the Gauss-Bonnet dark energy model and its deformed version on Ho\v{r}ava-Lifshitz cosmology, which belongs to the class of cosmologies obtained from the so-called projectable version of Ho\v{r}ava-Lifshitz gravity. In particular, we investigate the bulk/boundary interaction in this scenario through the $Q$ function, which we interpret as a measure of the energy transference between the bulk and the spacetime boundary. Then we discuss whether the thermal equilibrium will be stable or not, once it is reached, and the validity of the generalized second law. We show that the $Q$ function can exhibit sign changes along the cosmic evolution and the Universe reaches the thermal equilibrium as a transient phenomenon.