Maximally self-interacting dark matter: models and predictions

Understand

We study self-interacting dark matter (SIDM) scenarios, where the $s$-wave self-scattering cross section almost saturates the Unitarity bound.

• Such self-scattering cross sections are singly parameterized by the dark matter mass, and are featured by strong velocity dependence in a wide range of velocities.
• They may be indicated by observations of dark matter halos in a wide range of masses, from Milky Way's dwarf spheroidal galaxies to galaxy clusters.
• We pin down the model parameters that saturates the Unitarity bound in well-motivated SIDM models: the gauged $L_{\mu} - L_{\tau}$ model and composite asymmetric dark matter model.