Vector Inflation

TL;DR

This paper introduces a model where inflation is driven by non-minimally coupled massive vector fields, mimicking scalar field inflation, with implications for isotropy and late-time cosmic acceleration.

Contribution

It demonstrates that vector fields can drive inflation similarly to scalar fields and explores isotropy conditions and late-time acceleration effects.

Findings

Vector fields can produce isotropic inflation with orthogonal triplets or random orientations.

Anisotropy persists if many randomly oriented vector fields are used.

Light vector fields may explain late-time cosmic acceleration.

Abstract

We propose a scenario where inflation is driven by non-minimally coupled massive vector fields. In an isotropic homogeneous universe these fields behave in presicely the same way as a massive minimally coupled scalar field. Therefore our model is very similar to the model of chaotic inflation with scalar field. For vector fields the isotropy of expansion is achived either by considering a triplet of orthogonal vector fields or for the expense of $N$ randomly oriented vector fields. In the last case the substantial anisotropy of the expansion of order $1/\sqrt{N}$ survives until the end of inflation. The lightest vector fields might also force the late time acceleration of the Universe.