Observational Consequences of Dark Energy Decay

TL;DR

This paper explores a dark energy model originating from a first-order phase transition in a hidden sector, which could explain extra radiation and ISW correlations, with constraints from observational data and potential for future testing.

Contribution

It introduces a decay model of dark energy via a phase transition, providing new observational constraints and potential explanations for CMB anomalies.

Findings

Decay rate constrained by KSZ data

Model explains excess ISW correlations

Future surveys can further test the model

Abstract

We consider the generic scenario of dark energy which arises through the latent heat of a hidden sector first order cosmological phase transition. This field could account for the extra radiation degree of freedom suggested by the CMB. We present the bubble nucleation solution for the viscous limit. The decay rate of the field is constrained by published KSZ data, and may be an explanation of current excess ISW correlations. Cross correlation of current and future surveys can further constrain or test the parameter space. The decay model is plausibly in the observable range, and avoids anthropic problems. This class of models is not well constrained by the popular dark energy figure of merit.