Secular evolution of galaxies and galaxy clusters in decaying dark matter cosmology

TL;DR

This paper explores how decaying dark matter influences the long-term evolution of galaxies and clusters, potentially explaining observed changes in galaxy properties over cosmic time.

Contribution

It demonstrates that decaying dark matter can account for galaxy and cluster evolution phenomena while remaining consistent with observational constraints.

Findings

Decay of dark matter affects galaxy size and rotation relations.

Decaying dark matter explains elliptical galaxy size evolution.

Results align with current observational constraints.

Abstract

If the dark matter sector in the universe is composed by metastable particles, galaxies and galaxy clusters are expected to undergo significant secular evolution from high to low redshift. We show that the decay of dark matter, with a lifetime compatible with cosmological constraints, can be at the origin of the observed evolution of the Tully-Fisher relation of disk galaxies and alleviate the problem of the size-evolution of elliptical galaxies, while being consistent with the current observational constraints on the gas fraction of clusters of galaxies.