Hybrid Curvatons from Broken Symmetry

TL;DR

This paper introduces a novel hybrid mechanism combining curvatons and inhomogeneous preheating, where a globally symmetric field's slight symmetry breaking leads to curvature perturbations after inflation, with the curvaton being a preheat field.

Contribution

It proposes the first hybrid model linking curvatons with inhomogeneous preheating, where the curvaton is a preheat field with explicit mass, differing from traditional models.

Findings

Inhomogeneous preheating due to oscillating fields with broken symmetry.

Curvaton identified as a preheat field, not the oscillating field.

Explicit mass term for the curvaton influences evolution and decay.

Abstract

We present a new general mechanism for generating curvature perturbations after inflation. Our model is based on the simple assumption that a field that starts to oscillate after inflation has a potential characterized by an underlying global symmetry that is slightly or badly broken. Inhomogeneous preheating occurs due to the oscillation with the broken symmetry. Unlike the traditional curvaton model, we will not identify the curvaton with the oscillating field. The curvaton is identified with the preheat field that could be either a scalar, vector, or fermionic field. We introduce an explicit mass term for the curvaton, which is important for later evolution and the decay. Our present model represents the simplest example of the hybrid of the curvatons and inhomogeneous preheating.