Fall 2023 Physics Colloquium:- Probing dark matter self-interactions with collapsed dark matter halos
Over the past decades, we have accumulated compelling evidence for the existence of dark matter, yet its nature remains elusive. Dark matter could be part of the "dark sectors," comprising hidden particles with new interactions. These new particles and interactions can alter the formation and evolution of various small-scale structures in the Universe. This talk will focus on the impacts of dark matter self-interactions, a common feature within the dark sector paradigm, on the properties of dark matter halos. Self-interacting dark matter halos experience gravothermal evolution, where the central halo initially forms a core that ultimately collapses. The core-collapsed phase diversifies the density distributions of dark matter halos. It also showcases the universality in the evolution of self-interacting dark matter halos as thermal systems. Current and future observations, such as the James Webb Space Telescope and the Large Synoptic Survey Telescope, could probe the properties of the collapsed dark matter halos through strong lensing and weak lensing and shed light on dark matter self-interactions. Furthermore, the collapsed halos may give birth to the supermassive black holes observed at high redshifts, a longstanding puzzle in astrophysics.
地點：香港大學 本部大樓 MB237室
講者：Prof. ZHONG Yi-Ming 鍾益鳴 教授 (香港城巿大學)