Self-Interacting Dark Matter

TL;DR

This paper reviews the concept of self-interacting dark matter as a solution to small-scale structure issues, discusses recent numerical tests, and re-evaluates experimental constraints on its properties.

Contribution

It provides a comprehensive review of self-interacting dark matter, including recent numerical validations and updated experimental constraints on its interaction cross-section and mass.

Findings

Self-interacting dark matter can address small-scale structure discrepancies.

Recent numerical tests support the viability of self-interacting dark matter.

Experimental constraints narrow the parameter space for dark matter self-interactions.

Abstract

Spergel and Steinhardt have recently proposed the concept of dark matter with strong self-interactions as a means to address numerous discrepancies between observations of dark matter halos on subgalactic scales and the predictions of the standard collisionless dark matter picture. We review the motivations for this scenario and discuss some recent, successful numerical tests. We also discuss the possibility that the dark matter interacts strongly with ordinary baryonic matter, as well as with itself. We present a new analysis of the experimental constraints and re-evaluate the allowed range of cross-section and mass.