Anisotropic power-law inflation for a conformal-violating Maxwell model

TL;DR

This paper explores anisotropic power-law inflation solutions in a conformal-violating Maxwell model with a specific scalar-vector coupling, analyzing their stability and implications for cosmic anisotropy.

Contribution

It introduces new anisotropic power-law inflation solutions with a novel scalar-vector coupling and examines their stability, revealing conditions for persistent small anisotropy.

Findings

Unstable anisotropic solutions during inflation.

Existence of stable slowly expanding solutions with small anisotropy.

Results support the cosmic no-hair conjecture.

Abstract

A set of power-law solutions of a conformal-violating Maxwell model with a non-standard scalar-vector coupling will be shown in this paper. In particular, we are interested in a coupling term of the form $X^{2n} F^{\mu\nu}F_{\mu\nu}$ with $X$ denoting the kinetic term of the scalar field. Stability analysis indicates that the new set of anisotropic power-law solutions is unstable during the inflationary phase. The result is consistent with the cosmic no-hair conjecture. We show, however, that a set of stable slowly expanding solutions does exist for a small range of parameters $\lambda$ and $n$. Hence a small anisotropy can survive during the slowly expanding phase.