Can decaying dark matter scenarios alleviate both $H_0$ and $\sigma_8$ tensions?

TL;DR

This paper investigates whether decaying dark matter models can resolve the tensions in H_0 and sigma_8 measurements, concluding that such models are unlikely to be effective solutions.

Contribution

It explores a broad class of decaying dark matter scenarios and tests their ability to alleviate cosmological tensions using CMB data.

Findings

Decaying dark matter does not significantly alleviate H_0 tension.

Decaying dark matter models are inconsistent with current CMB data.

The study narrows down the viability of non-CDM models for cosmological tensions.

Abstract

Current tensions in cosmology, including $H_0$ and $\sigma_8$, provide one of the strong reasons to suspect the existence of physics beyond the standard model of cosmology ($\Lambda$CDM). In this paper, we investigate if there is a relation between these tensions and beyond cold dark matter scenarios. To model non-CDM, we assume a decaying dark matter (DDM) which is unstable and may decay into two daughter particles, a combination of cold dark matter, warm dark matter, and dark radiation, to explore a vast era of possibilities. We checked our model against CMB data and could show that decaying dark matter seems not a promising candidate to address the cosmological tensions.