skip to main content

Title: Constraining dark matter late-time energy injection: decays and p-wave annihilations

We use the latest cosmic microwave background (CMB) observations to provide updated constraints on the dark matter lifetime as well as on p-wave suppressed annihilation cross sections in the 1 MeV to 1 TeV mass range. In contrast to scenarios with an s-wave dominated annihilation cross section, which mainly affect the CMB close to the last scattering surface, signatures associated with these scenarios essentially appear at low redshifts (z∼<50) when structure began to form, and thus manifest at lower multipoles in the CMB power spectrum. We use data from Planck, WMAP9, SPT and ACT, as well as Lyman–α measurements of the matter temperature at z ∼ 4 to set a 95% confidence level lower bound on the dark matter lifetime of ∼ 4 × 10{sup 25} s for m{sub χ} = 100 MeV. This bound becomes lower by an order of magnitude at m{sub χ} = 1 TeV due to inefficient energy deposition into the intergalactic medium. We also show that structure formation can enhance the effect of p-wave suppressed annihilation cross sections by many orders of magnitude with respect to the background cosmological rate, although even with this enhancement, CMB constraints are not yet strong enough to reach themore » thermal relic value of the cross section.« less
Authors:
; ; ;  [1] ;  [2]
  1. Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain)
  2. Theoretische Natuurkunde Vrije Universiteit Brussel and The International Solvay Institutes Pleinlaan 2, B-1050 Brussels (Belgium)
Publication Date:
OSTI Identifier:
22369771
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANNIHILATION; CROSS SECTIONS; GEV RANGE; MEV RANGE; NONLUMINOUS MATTER; P WAVES; RELICT RADIATION; S WAVES