Astroparticle Seminar

Constraining annihilating and decaying Dark Matter with the Cosmic Microwave Background

Aaron Vincent

Universitat de València

CMB photons, emitted at a redshift z ~ 1100, are sensitive to heating or ionization of the intergalactic medium (IGM) along their paths. I will review how energy injection into the IGM from the annihilation or decay of dark matter can measurably alter the temperature and polarization power spectra of the CMB. This requires accurate modelling of recombination, reheating and structure formation. Specifically, I will discuss long-lived decaying dark matter, as well as DM which annihilates via either an s-wave or a p-wave process. I will show that in the latter case, the homogeneous background contribution is much smaller than the effect of dark matter halos, whose late-time formation considerably enhances annihilation, leading to large qualitative differences in the CMB power spectrum. Finally, I will present updated constraints using data from the Planck, WMAP9, SPT and ACT experiments. Based on arXiv:1303.5094 and arXiv:1308.2578.