When dark matter meets dark matter: Searching for hints of dark matter self-interactions in galaxy clusters

Dark matter constitutes ~85% of the matter content in the Universe, providing the gravitational backbone of cosmic structure formation. With in-depth analysis led by frontier facilities, tensions have been reported between the observed Universe and predictions from the latest hydrodynamical simulations on small scales, motivating an alternative model of dark matter. In this talk, I will introduce recent efforts in testing the self-interacting nature of dark matter using galaxy clusters, the most massive virialized systems in the Universe. Specifically, I will highlight recent progress from our work combining multi-wavelength observations with numerical simulations of merging galaxy clusters to reconstruct their merger histories and place constraints on dark matter self-interactions.