Using Cosmic Shear to Constrain a Hot Dark Matter Sub-Species

by Mr Fabian Hervas Peters (CNRS)

Wednesday 20 Sept 2023, 13:30 → 14:30 Europe/Stockholm

Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

In this talk I describe the potential of the cosmic shear power spectrum to constrain a mixed (hot plus cold) dark matter scenario with two additional free parameters, the hot-to-total dark matter fraction and the thermal mass of the hot component. Next to providing limits, I discuss the potential of mixed dark matter to address the clustering (or S8) tension between lensing and the CMB, finding a significant reduction of the said tension. I will also describe recent progress in cosmic shear modelling regarding the key systematics of intrinsic alignment and baryonic feedback effects and their impact on the S8 value. If time permits, I will present analogous work constraining decaying dark matter with cosmic shear observations.

Peters_2023-09-20.mp4