Astroparticle seminar: Laura Lopez

(Vrije Universiteit Brussel)

Dark matter imprint in the epoch of reionisation and the dark ages

In my talk I will consider two possible ways in which the dark matter can affect the evolution of of the history of the universe along the epoch of reionization and the dark ages. First, in warm dark matter scenarios, the structure formation is expected to be   suppressed on small scales with respect to the cold dark matter case, reducing the number of low-mass halos and the fraction of ionized gas at high redshifts and thus, delaying reionization. This has an impact on the ionization history of the Universe and measurements of the optical depth to reionization, of the evolution of the global fraction of ionized gas and of the thermal history of the intergalactic medium. Second, in any dark matter scenario, the dark matter can inject energy in the intergalactic medium through annihilation or decay. We will turn our attention to annihilating cold dark matter and look at its imprint on future cosmological probe such as the redshifted 21cm signal.