Gamma rays from dark matter

TL;DR

This paper reviews how gamma-ray observations can help detect dark matter particles through their annihilation signatures, highlighting the potential of current and future telescopes to explore dark matter properties.

Contribution

It provides a comprehensive overview of gamma-ray detection methods for dark matter, emphasizing spectral signatures and the complementarity of indirect and direct searches.

Findings

Gamma-ray spectral signatures can distinguish dark matter from astrophysical backgrounds.

Current telescopes like Fermi can probe significant dark matter parameter space.

Indirect and direct detection methods are complementary in dark matter searches.

Abstract

A leading hypothesis for the nature of the elusive dark matter are thermally produced, weakly interacting massive particles that arise in many theories beyond the standard model of particle physics. Their self-annihilation in astrophysical regions of high density provides a potential means of indirectly detecting dark matter through the annihilation products, which nicely complements direct and collider searches. Here, I review the case of gamma rays which are particularly promising in this respect: distinct and unambiguous spectral signatures would not only allow a clear discrimination from astrophysical backgrounds but also to extract important properties of the dark matter particles; powerful observational facilities like the Fermi Gamma-ray Space Telescope or upcoming large, ground-based Cherenkov telescope arrays will be able to probe a considerable part of the underlying, e.g. supersymmetric, parameter space. I conclude with a more detailed comparison of indirect and direct dark matter searches, showing that these two approaches are, indeed, complementary.