Symmetries of Vector Perturbations during the de Sitter Epoch

TL;DR

This paper investigates the symmetries of vector perturbations during the de Sitter epoch, focusing on models with inflaton-vector couplings that produce scale-invariant vector fluctuations, using conformal symmetry to analyze correlators.

Contribution

It characterizes the correlators of inflaton and vector fields during de Sitter using conformal symmetry, providing a symmetry-based framework for understanding vector perturbations.

Findings

Vector perturbations can be scale-invariant with suitable inflaton-vector couplings.

De Sitter isometry acts as a conformal group on super-Hubble scales.

Correlators involving inflaton and vector fields are constrained by conformal symmetry.

Abstract

We analyze the class of models where a suitable coupling between the inflaton field and the vector field gives rise to scale-invariant vector perturbations. We exploit the fact that the de Sitter isometry group acts as conformal group on the three-dimensional Euclidean space for the super-Hubble fluctuations in order to characterize the correlators involving the inflaton and the vector fields.