Forming the first stars amidst decaying and annihilating dark matter

          @misc{ scivideos_PIRSA:24020076,
            doi = {10.48660/24020076},
            url = {https://pirsa.org/24020076},
            author = {Qin, Wenzer},
            keywords = {Cosmology},
            language = {en},
            title = {Forming the first stars amidst decaying and annihilating dark matter},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2024},
            month = {feb},
            note = {PIRSA:24020076 see, \url{https://scivideos.org/index.php/pirsa/24020076}}
          }
          

Abstract

The first stars are expected to form through molecular-hydrogen (H2) cooling, a channel that is especially sensitive to the thermal and ionization state of gas, and can thus act as a probe of exotic energy injection from decaying or annihilating dark matter (DM). I will discuss using a toy halo model to study the impact of DM-sourced energy injection on the H2 content of the first galaxies, and thus estimate the threshold mass required for a halo to form stars at high redshifts. I will show that currently allowed DM models can significantly change this threshold, producing both positive and negative feedback and estimate how this can impact the timing of 21cm signals at cosmic dawn.