Dynamical friction in Bose-Einstein condensed self-interacting dark matter at finite temperatures, and the Fornax dwarf spheroidal

Understand

The aim of the present work is to better understand the gravitational drag forces, i.e.

• dynamical friction, acting on massive objects moving through a self-interacting Bose-Einstein condensate, also known as a superfluid, at finite temperatures.
• This is relevant for light scalar models of dark matter with weak self-interactions that require nonzero temperatures, or that have been heated inside galaxies.
• We derived expressions for dynamical friction using linear perturbation theory, and compared these to numerical simulations in which nonlinear effects are included.