Cubic Derivative Interactions and Asymptotic Dynamics of the Galileon Vacuum

TL;DR

This paper uses dynamical systems theory to analyze the asymptotic behavior of vacuum galileon models with cubic derivative interactions, revealing late-time phantom attractors and the absence of self-accelerating solutions.

Contribution

It provides a detailed dynamical analysis of vacuum galileon models with cubic interactions, highlighting their unique late-time behavior and differences from matter-influenced scenarios.

Findings

Late-time phantom attractor with big rip singularity

Vacuum galileon interactions modify cosmic dynamics at late times

No self-accelerating solutions in this model

Abstract

In this paper we apply the tools of the dynamical systems theory in order to uncover the whole asymptotic structure of the vacuum interactions of a galileon model with a cubic derivative interaction term. It is shown that, contrary to what occurs in the presence of background matter, the galileon interactions of vacuum appreciably modify the late-time cosmic dynamics. In particular, a local late-time attractor representing phantom behavior arises which is inevitably associated with a big rip singularity. It seems that the gravitational interactions of the background matter with the galileon screen the effects of the gravitational self-interactions of the galileon, thus erasing any potential modification of the late-time dynamics by the galileon vacuum processes. Unlike other galileon models inspired in the DGP scenario, self-accelerating solutions do not arise in this model.