Interacting Dark Energy in Ho\v{r}ava-Lifshitz Cosmology

TL;DR

This paper extends Hořava-Lifshitz cosmology to include interactions between scalar fields representing dark matter and dark energy, demonstrating that such interactions can produce phantom-like dark energy behavior with an effective equation of state less than -1.

Contribution

It introduces a model with interacting scalar fields in Hořava-Lifshitz cosmology, showing that interactions can lead to phantom dark energy, unlike previous non-interacting models.

Findings

Interaction induces phantom dark energy behavior

Effective equation of state w_d^{eff} < -1 due to interaction

Interaction effects are distinct from non-interacting models

Abstract

In the usual Ho\v{r}ava-Lifshitz cosmological models, the scalar field is responsible for dark matter. Using an additional scalar field, Saridakis \cite{sari} has formulated Ho\v{r}ava-Lifshitz cosmology with an effective dark energy sector. In the paper \cite{sari} the scalar fields do not interact with each other, here we extend this work to the interacting case, where matter scalar field $\phi$ interact with dark energy scalar field $\sigma$. We will show that in contrast with \cite{sari}, where $\sigma$-filed is absent, we can obtain $w_d ^{\rm eff}<-1$, that is we result to an effective dark energy presenting phantom behaviour. This behaviour is pure effect of the interaction.