Speaker
Description
Self-Interacting Dark Matter (SIDM) is a compelling alternative to Cold Dark Matter that may alleviate the well-known “small scale problems” that arise when comparing simulations to observations of low-mass galaxies. We study SIDM in isolated low-mass galaxies using a novel suite of cosmological high-resolution simulations. We compare the core density evolution, driven by self-interactions, of simulated halos with that predicted by analytic models. Our results reveal that in the absence of mergers, low-mass halos follow analytic models for gravothermal collapse. However, when subhalos of comparable mass fall into the core of the host halo, gravothermal collapse is delayed, often beyond the age of the universe. These findings indicate that accounting for mergers is essential when evaluating the viability of SIDM models in low-mass halos, with implications for interpreting the observed density profiles of both Milky Way satellite galaxies and isolated field galaxies.