Limits on Self-Interacting Dark Matter

TL;DR

This paper establishes new, stringent constraints on fermionic asymmetric dark matter self-interactions by analyzing neutron star observations, significantly tightening previous bounds and impacting dark matter models.

Contribution

It introduces novel constraints on WIMP self-interactions derived from neutron star data, surpassing previous limits from galaxy cluster observations.

Findings

Constraints on WIMP self-interactions are several orders of magnitude stricter than Bullet Cluster limits.

Neutron stars can accrete enough WIMPs to potentially form mini black holes and destroy the star.

New bounds significantly restrict viable dark matter models with self-interactions.

Abstract

We impose new severe constraints on the self-interactions of fermionic asymmetric dark matter based on observations of nearby old neutron stars. WIMP self-interactions mediated by Yukawa- type interactions can lower significantly the number of WIMPs necessary for gravitational collapse of the WIMP population accumulated in a neutron star. Even nearby neutron stars located at regions of low dark matter density can accrete sufficient number of WIMPs that can potentially collapse, form a mini black hole, and destroy the host star. Based on this, we derive constraints on the WIMP self-interactions which in some cases are by several orders of magnitude stricter than the ones from the bullet cluster (which are currently considered the most stringent).