High Energy Physics Seminar

Worldwide efforts to directly detect dark matter (DM) have placed increasingly stringent limits on DM's interactions with ordinary matter. It is possible that these interactions are simply too feeble to practically detect. Meanwhile, DM self-interactions and DM-neutrino interactions remain relatively unprobed. Observable consequences of such "dark forces" might offer the first clues as to the nature of DM. In the first part of the talk, I will explain how cosmology sets the strongest constraints yet on long-range DM self-interactions at length scales shorter than 100 kpc. In the second part, I will discuss the early-universe dynamics of an ultralight scalar DM coupled to neutrinos, focusing on the dissipative backreaction of the neutrinos on the scalar, an effect not considered previously.

The talk is in 469 Lauritsen.

Contact [email protected] for Zoom link.