Anisotropic Power-law Inflation: A counter example to the cosmic no-hair conjecture

TL;DR

This paper presents an exact anisotropic power-law inflation solution in supergravity that challenges the cosmic no-hair conjecture, showing anisotropy can persist during inflation.

Contribution

It provides a counterexample to the cosmic no-hair conjecture by demonstrating anisotropic inflation as a generic attractor in supergravity models.

Findings

Anisotropic inflation can be an attractor solution.

Counterexample to the cosmic no-hair conjecture in supergravity.

Anisotropic sources can sustain anisotropy during inflation.

Abstract

It is widely believed that anisotropy in the expansion of the universe will decay exponentially fast during inflation. This is often referred to as the cosmic no-hair conjecture. However, we find a counter example to the cosmic no-hair conjecture in the context of supergravity. As a demonstration, we present an exact anisotropic power-law inflationary solution which is an attractor in the phase space. We emphasize that anisotropic inflation is quite generic in the presence of anisotropic sources which couple with an inflaton.