Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects

TL;DR

This review discusses gamma-ray signals as a promising method for detecting dark matter, focusing on spectral signatures, current search status, and future prospects, including potential evidence for a 130 GeV line.

Contribution

It provides a comprehensive overview of gamma-ray signatures of dark matter, updates on current searches, and evaluates the implications of potential signals like the 130 GeV line.

Findings

Gamma-ray signatures are promising for dark matter detection.

Current searches have identified potential signals like the 130 GeV line.

Future gamma-ray observations could confirm dark matter particle properties.

Abstract

Weakly interacting massive particles (WIMPs) remain a prime candidate for the cosmological dark matter (DM), even in the absence of current collider signals that would unambiguously point to new physics below the TeV scale. The self-annihilation of these particles in astronomical targets may leave observable imprints in cosmic rays of various kinds. In this review, we focus on gamma rays which we argue to play a pronounced role among the various possible messengers. We discuss the most promising spectral and spatial signatures to look for, give an update on the current state of gamma-ray searches for DM and an outlook concerning future prospects. We also assess in some detail the implications of a potential signal identification for particle DM models as well as for our understanding of structure formation. Special emphasis is put on the possible evidence for a 130 GeV line-like signal that was recently identified in the data of the Fermi gamma-ray space telescope.