Generalised DBI-Quintessence

TL;DR

This paper explores the complex phase space of a generalized DBI quintessence model, revealing its potential as a viable k-essence candidate with diverse dynamical behaviors.

Contribution

It introduces a generalized DBI action for quintessence and analyzes its phase space, uncovering richer dynamics and broader equation of state coverage than previous models.

Findings

Full equation of state parameter space covered (-1 to 1)

Discovery of many non-trivial solution curves

Indication of DBI quintessence as a promising k-essence candidate

Abstract

We investigate the phase space of a quintessence theory governed by a generalised version of the DBI action, using a combination of numeric and analytic methods. The additional degrees of freedom lead to a vastly richer phase space structure, where the field covers the full equation of state parameter space; $-1 \le \omega \le 1$. We find many non-trivial solution curves to the equations of motion which indicate that DBI quintessence is an interesting candidate for a viable k-essence model.