On the Tremaine-Gunn Limit with Mass-Varying Particles

TL;DR

This paper extends the Tremaine-Gunn limit to scenarios where dark matter particle masses vary over time, analyzing the impact on cosmological constraints and detection prospects.

Contribution

It generalizes phase-space density limits for mass-varying dark matter particles and explores their cosmological and detection implications.

Findings

Generalized Tremaine-Gunn limit for mass-varying particles

Implications for dark matter equation of state

Effects on indirect detection strategies

Abstract

General classical arguments on the time evolution of the phase-space density can be used to derive constraints on the mass of particle candidates for the cosmological dark matter (DM). The resulting Tremaine-Gunn limit is extremely useful in constraining particle DM models. In certain models, however, the DM particle mass varies appreciably over time. In this work, we generalize the phase-space limits on possible DM particle masses to these scenarios. We then examine the ensuing cosmological implications on the effective DM equation of state and indirect DM detection.