Anisotropic brane cosmologies with exponential potentials

TL;DR

This paper investigates anisotropic brane cosmologies with exponential scalar potentials, analyzing conditions for inflation and how extra dimensions and anisotropy influence late-time behavior, especially in multi-field models.

Contribution

It provides a detailed analysis of Bianchi I brane cosmologies with exponential potentials, including multi-field generalizations and their impact on inflation and anisotropy decay.

Findings

Anisotropy effects diminish faster than extra-dimensional effects.

Multiple scalar fields facilitate inflation in brane cosmologies.

Late-time behavior shows negligible influence of initial anisotropy.

Abstract

We study Bianchi I type brane cosmologies with scalar matter self-interacting through combinations of exponential potentials. Such models correspond in some cases to inflationary universes. We discuss the conditions for accelerated expansion to occur, and pay particular attention to the influence of extra dimensions and anisotropy. Our results show that the associated effects evolve in such a way that they become negligible in the late time limit, those related to the anisotropy disappearing earlier. This study focuses mainly on single field models, but we also consider a generalization yielding models with multiple non-interacting fields and examine its features briefly. We conclude that in the brane scenario, as happens in general relativity, an increase in the number of fields assists inflation.