Interacting dark energy in Hořava-Lifshitz cosmology

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.