Vector Field and Inflation

TL;DR

This paper explores whether a timelike vector field with specific kinetic and potential conditions can induce an inflationary phase in the early universe, providing a potential alternative to scalar-driven inflation models.

Contribution

It introduces a framework for vector field-driven inflation with a general quadratic kinetic term and analyzes conditions for successful inflation.

Findings

Vector fields can produce accelerated expansion under certain conditions.

Massive and small field vector potentials satisfy inflation criteria.

The model maintains isotropy with a timelike vector field.

Abstract

We have investigated if the vector field can give rise to an accelerating phase in the early universe. We consider a timelike vector field with a general quadratic kinetic term in order to preserve an isotropic background spacetime. The vector field potential is required to satisfy the three minimal conditions for successful inflation: i) $\rho>0$, ii) $\rho+3P < 0$ and iii) the slow-roll conditions. As an example, we consider the massive vector potential and small field type potential as like in scalar driven inflation.