Sommerfeld enhancement of invisible dark matter annihilation in galaxies and galaxy clusters

TL;DR

This paper proposes that Sommerfeld enhancement of dark matter annihilation into sterile neutrinos can explain core-like structures in galaxies, matching observations and predicting observable effects in dwarf galaxies.

Contribution

It introduces a model where Sommerfeld enhancement explains core structures in galaxies through dark matter annihilation into sterile neutrinos, aligning with empirical data.

Findings

Core density and radius match observational fits

Enhanced annihilation rates solve the core-cusp problem

Predicted observable effects in dwarf galaxies

Abstract

Recent observations indicate that core-like dark matter structures exist in many galaxies, while numerical simulations reveal a singular dark matter density profile at the center. In this article, I show that if the annihilation of dark matter particles gives invisible sterile neutrinos, the Sommerfeld enhancement of the annihilation cross-section can give a sufficiently large annihilation rate to solve the core-cusp problem. The resultant core density, core radius, and their scaling relation generally agree with recent empirical fits from observations. Also, this model predicts that the resultant core-like structures in dwarf galaxies can be easily observed, but not for large normal galaxies and galaxy clusters.