Current Status of Self-Interacting Dark Matter

Explore a theoretical physics colloquium that delves into the current understanding of self-interacting dark matter (SIDM) and its role in structure formation across the Universe. Learn about gravitational probes as alternative methods for dark matter detection, given the absence of conventional signals. Examine how observations of dark matter halos across various mass scales - from ultra-faint dwarf galaxies to galaxy clusters - suggest velocity-dependent self-interaction cross sections. Discover two compelling scenarios where self-interaction appears either extremely strong or resonant, and understand their compatibility with existing observational data. Investigate the evolution patterns of dark matter halos and potential observational signatures that could validate these theoretical frameworks.