Cosmological constraints on late-universe decaying dark matter as a solution to the $H_0$ tension

TL;DR

This paper investigates whether late-universe decaying dark matter can resolve the H_0 tension, but finds that cosmic microwave background data strongly limits this possibility.

Contribution

It provides a detailed analysis showing that CMB anisotropy measurements constrain late-decaying dark matter as a solution to the H_0 tension.

Findings

CMB low multipole data restricts late-decaying dark matter models.

Decaying dark matter cannot easily resolve the H_0 tension due to observational constraints.

The study narrows down viable dark matter decay scenarios for cosmological models.

Abstract

It has been suggested that late-universe dark matter decays can alleviate the tension between measurements of $H_0$ in the local universe and its value inferred from cosmic microwave background fluctuations. It has been suggested that decaying dark matter can potentially account for this discrepancy as it reshuffles the energy density between matter and radiation and as a result allows dark energy to become dominant at earlier times. In this work, we show that the low multipole amplitude of the cosmic microwave background anisotropy power spectrum severely constrains the feasibility of late-time decays as a solution to the $H_0$ tension.