Seminarium "Teoria cząstek elementarnych i kosmologia"

In the talk, I will revisit the possibility of using cosmological observations to constrain models that involve interactions between neutrinos and dark matter. I will show that small-scale measurements of the cosmic microwave background with a few percent accuracy are critical to uncovering unique signatures from models with small couplings that would require a much higher sensitivity at lower multipoles. In order to test this, the currently available high-multipole data have been analyzed, both independently and in combination with low-multipole CMB and Baryon Acoustic Oscillation measurements, finding a preference for a non-vanishing coupling at 68% CL. This aligns with other CMB-independent probes, such as Lyman-α. I will illustrate how this coupling could be accounted for in dark matter interactions with a sterile neutrino.