Title: New Insight on Neutrino Dark Matter Interactions from Small-Scale CMB Observations

Speaker: Dr. Sebastian Trojanowski (National Centre for Nuclear Research)

Time: 14:00pm, NDecember 7, 2023

Location: 3-201, PMO Xianlin Campus

Abstract: 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 tiny couplings that would require a much higher sensitivity at lower multipoles, such as those probed by the Planck satellite. In order to test this, the high-multipole data released by the Atacama Cosmology Telescope have been analyzed, both independently and in combination with Planck 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.(arXiv: 2303.16895)