Modulated decay in the multi-component Universe

TL;DR

This paper investigates how modulated decay of multiple components in the early Universe can generate curvature perturbations, considering complex scenarios with various energy density components and their decay behaviors.

Contribution

It introduces a comprehensive analysis of curvature perturbation generation via modulated decay in a multi-component early Universe, expanding on previous single-component models.

Findings

Curvature perturbations can be significantly affected by the decay modulation of multiple components.

Different density scalings of components lead to diverse perturbation outcomes.

The study provides a framework for understanding perturbation generation in complex early Universe scenarios.

Abstract

The early Universe after inflation may have oscillations, kinations (nonoscillatory evolution of a field), topological defects, relativistic and non-relativistic particles at the same time. The Universe whose energy density is a sum of those components can be called the multi-component Universe. The components, which may have distinguishable density scalings, may decay modulated. In this paper we study generation of the curvature perturbations caused by the modulated decay in the multi-component Universe.