Dark matter decay signals in cosmic filaments
Phys. Rev. D 113, 095036 – Published 27 May, 2026
DOI: https://doi.org/10.1103/cf16-3hf5
Abstract
Cosmic filaments form the backbone of the cosmic web, yet their properties and evolution remain uncertain. We demonstrate that filaments provide a novel target for dark matter indirect detection. Using the Evolution and Assembly of Galaxies and their Environments hydrodynamical simulations, we investigate the dark matter density profiles in filaments and their implications for dark matter decay signals. We show that GeV-scale dark matter particles decaying into electron-positron pairs can produce detectable radio synchrotron emission. By leveraging stacked filament radio data, we place stringent constraints on the dark matter decay lifetime, improving existing limits by up to 2 orders of magnitude for strong filamentary magnetic fields. This work highlights cosmic filaments as a promising probe for dark matter, with implications for broader large-scale structure and cosmological simulation communities.
