Cosmological constraints on TeV-scale dark matter subcomponents decaying between recombination and reionisation

Journal of Cosmology and Astroparticle Physics, vol. 2026, pp. 099

Abstract

Abstract The Dark Ages and the Cosmic Dawn are an untapped well of information about the particle physics properties of dark matter, which may become accessible with future radio telescopes able to probe the 21-cm signal from atomic hydrogen. In this work we study the impact on cosmological observables of a dark matter subcomponent composed of TeV-scale particles that decay into electrons, photons or neutrinos with a lifetime shorter than the age of the universe. We re-evaluate constraints from the Cosmic Microwave Background (CMB) on these scenarios using the most recent data sets and estimate the sensitivity of future detections of the global 21-cm signal. Our main result is that the latter is potentially more sensitive to the effects of decaying dark matter with a lifetime τ ≳ 10 15 s. This effect is strongest for the case of decays into neutrinos due to the different spectral distribution of the injected electromagnetic energy. For DM masses well above the TeV-scale, these differences become less pronounced and the sensitivity of both the CMB and the 21-cm signal depend primarily on the total amount of injected electromagnetic energy.

Authors 3

1. Markus R. Mosbech Aachen Institute for Theoretical Particle Physics and Cosmology

   RWTH Aachen University · Karlsruhe Institute of Technology

   Affiliation as printed

   Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe,

   Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, D-52056 Aachen,

2. Cristina Benso

   Karlsruhe Institute of Technology

   Affiliation as printed

   Institute for Astroparticle Physics (IAP) Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen,

   Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe,

3. Felix Kahlhoefer

   Karlsruhe Institute of Technology

   Affiliation as printed

   Institute for Astroparticle Physics (IAP) Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen,

   Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe,