Angular correlations in the cosmic gamma-ray background from dark matter annihilation around intermediate-mass black holes

TL;DR

This paper explores how angular correlations in the cosmic gamma-ray background can help identify dark matter annihilation signals, especially around intermediate-mass black holes, using Fermi telescope data.

Contribution

It demonstrates that angular correlation analysis can distinguish dark matter signals from astrophysical backgrounds in gamma-ray data, focusing on mini-spikes around black holes.

Findings

Angular correlations can separate dark matter signals from astrophysical backgrounds.

Detection prospects depend on dark matter mass and annihilation channels.

Fermi telescope has potential to detect these signals under certain conditions.

Abstract

Dark matter (DM) annihilation could in principle contribute to the diffuse cosmic gamma-ray back- ground (CGB). While with standard assumptions for cosmological and particle physics parameters this contribution is expected to be rather small, a number of processes could boost it, including a larger-than-expected DM annihilation cross-section, or the occurance of DM substructures such as DM mini-spikes around intermediate-mass black holes. We show that angular correlations of the CGB provide a tool to disentangle the signal induced by DM annihilation in mini-spikes from a conventional astrophysical component. Treating blazars as a known background, we study the prospects for detecting DM annihilations with the Fermi Gamma-Ray Space Telescope for different choices of DM mass and annihilation channels.