3-3-1 Self Interacting Dark Matter and the Galaxy Core-Cusp problem

TL;DR

This paper explores how self-interacting dark matter, possibly arising from a 3-3-1 extension of the standard model, can address the galaxy core-cusp problem by smoothing out dark matter density profiles in galactic centers.

Contribution

It introduces a novel formulation of self-interacting dark matter from the 3-3-1 model and presents new galaxy formation simulations to test its effects.

Findings

Self-interacting dark matter can flatten the dark matter density profile in galaxy centers.

Simulations show compatibility of 3-3-1 SIDM with observed galaxy core profiles.

Current constraints limit the parameter space of this SIDM model.

Abstract

The core-cusp problem remains as a challenging discrepancy between observations and simulations in the standard $\Lambda$CDM model for the formation of galaxies. The problem is that $\Lambda$CDM simulations predict a steep power-law mass density profile at the center of galactic dark matter halos. However, observations of dwarf galaxies in the Local Group reveal a density profile consistent with a nearly flat distribution of dark matter near the center. A number of solutions to this dilemma have been proposed. Here, we summarize investigations into the possibility that the dark matter particles themselves self interact and scatter. Such self-interacting dark matter (SIDM) particles can smooth out the dark-matter profile in high-density regions. We also review the theoretical proposal that self-interacting dark matter may arise as an additional Higgs scalar in the 3-3-1 extension of the standard model. We present new simulations of galaxy formation and evolution for this formulation of self-interacting dark matter. Current constraints on this self-interacting dark matter are then summarized.