The phase portrait of a matter bounce in Horava-Lifshitz cosmology

Understand

The occurrence of a bounce in FRW cosmology requires modifications of general relativity.

• An example of such a modification is the recently proposed Horava-Lifshitz theory of gravity, which includes a ``dark radiation'' term with a negative coefficient in the analog of the Friedmann equation.
• This paper describes a phase space analysis of models of this sort with the aim of determining to what extent bouncing solutions can occur.
• A simplification, valid in the relevant region, allows a reduction of the dimension of phase space so that visualization in three dimensions is possible.