Dirac-Born-Infeld Field Trapped in the Braneworld

TL;DR

This paper uses dynamical systems methods to analyze the cosmic evolution of a Dirac-Born-Infeld field in braneworld models, revealing stable solutions and attractors in different scenarios.

Contribution

It applies dynamical systems analysis to DBI fields in braneworld models, identifying stability and attractor solutions specific to Randall-Sundrum and DGP frameworks.

Findings

Matter-scaling solutions emerge in ultra-relativistic limit

Empty universe is the past attractor in one scenario

Matter-dominated phase is the past attractor in another

Abstract

We apply the dynamical systems tools to study the (linear) cosmic dynamics of a Dirac-Born-Infeld-type field trapped in the braneworld. We focus,exclusively, in Randall-Sundrum and in Dvali-Gabadadze-Porrati brane models. We analyze the existence and stability of asymptotic solutions for the AdS throat and the quadratic potential and a particular choice of the warp factor and of the potential for the DBI field ($f(\phi)=1/V(\phi)$). It is demonstrated, in particular, that in the ultra-relativistic approximation matter-scaling and scalar field-dominated solutions always arise. In the first scenario the empty universe is the past attractor, while in the second model the past attractor is the matter-dominated phase.