# Dark matter component decaying after recombination: constraints from diffuse gamma-ray and neutrino flux measurements

## TL;DR

This paper investigates a two-fraction dark matter model with an unstable component decaying after recombination, using gamma-ray and neutrino flux data to constrain decay channels and assess its cosmological implications.

## Contribution

It provides new constraints on decay channels of unstable dark matter fractions based on diffuse gamma-ray and neutrino flux measurements, testing a scenario that may resolve cosmological measurement tensions.

## Key findings

- Constraints on decay branching ratios for various channels.
- Limits on the lifetime of the unstable dark matter component.
- Implications for cosmological models with decaying dark matter.

## Abstract

We consider scenario of the dark matter consisting of two fractions, stable part being dominant and a smaller unstable fraction, which has decayed after the recombination epoch. It has been suggested in Ref. [arxiv:1505.03644] that the above scenario may alleviate tension between high-redshift (CMB anisotropy) and low-redshift (cepheid variables and SNe Ia, cluster counts) cosmological measurements. We derive constraints on the heavy relics branching to $q\bar{q}$, $e^+e^-$, $\mu^+\mu^-$, $\tau^+\tau^-$, $\nu_e\bar{\nu_e}$, $\nu_\mu\bar{\nu_\mu}$, $W^+W^-$ and $\gamma\gamma$ in the above scenario by comparison of the secondary $\gamma$ and $\nu$ fluxes produced by the process with recent diffuse $\gamma$ and $\nu$ flux measurements.