Inflation in a scalar-vector gravity theory

TL;DR

This paper investigates inflation driven by combined scalar and vector fields within a gravity theory, deriving analytical solutions, conditions for model viability, and constraining parameters using cosmological observations.

Contribution

It introduces a scalar-vector inflation model with analytical solutions and discusses conditions for its realization, incorporating observational constraints.

Findings

Analytical solutions for scalar-vector inflation during slow-roll.

Conditions for the physical viability of the models.

Constraints on model parameters from cosmological data.

Abstract

We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct scenarios: one where the fields interact and another where they do not. In this context, we find different analytical solutions to the background scalar-vector fields dynamics during the inflationary scenario considering the slow-roll approximation. Besides, general conditions required for these models of two fields to be realizable are determined and discussed. From the cosmological perturbations, we consider a local field rotation, and then we determine these perturbations (scalar and tensor) during inflation, and we also utilize recent cosmological observations for constraining the parameter-space in these scalar-vector inflationary models.