Phenomenological Aspects of Horava-Lifshitz Cosmology

TL;DR

This paper explores how Horava-Lifshitz quantum gravity modifies radiation energy density scaling in cosmology, potentially affecting baryon asymmetry and gravitational waves, and discusses observational constraints on these effects.

Contribution

It introduces a novel cosmological impact of Horava-Lifshitz dispersion relation, showing altered radiation scaling and its implications for early universe phenomena.

Findings

Radiation energy density scales as a^{-6} under Horava-Lifshitz dispersion.

Enhanced baryon asymmetry and stochastic gravitational waves predicted.

Discussion of observational constraints on the modified dispersion relation.

Abstract

We show that, assuming the dispersion relation proposed recently by Horava in the context of quantum gravity, radiation energy density exhibits a peculiar dependence on the scale factor; the radiation energy density decreases proportional to a^{-6}. This simple scaling can have an impact on cosmology. As an example, we show that the resultant baryon asymmetry as well as the stochastic gravity waves can be enhanced. We also discuss current observational constraint on the dispersion relation.