Anisotropic Cosmology and (Super)Stiff Matter in Ho\v{r}ava's Gravity Theory

TL;DR

This paper explores anisotropic cosmological solutions in Hořava gravity, revealing the role of super-stiff matter and the impact on cosmological collapse, with solutions applicable across multiple spatial dimensions.

Contribution

It provides new Kasner-type solutions in Hořava gravity for any number of spatial dimensions, linking anisotropic exponents to the coupling bb and analyzing super-stiff matter effects.

Findings

Kasner solutions valid for any spatial dimensions

Relation involving the coupling bb and exponents

Prediction of super-stiff matter with w d 1

Abstract

We study anisotropic cosmology in Ho\v{r}ava's gravity theory and obtain Kasner type solutions, valid for any number d of spatial dimensions. The corresponding exponents satisfy two relations, one involving the marginal coupling \lambda. Also, Ho\v{r}ava's (super)renormalisable theory predicts (super)stiff matter whose equation of state is p = w \rho with w \ge 1. We discuss briefly the implications of these results for the nature of cosmological collapse.