Data: 15.09.2022

Palestrante: Dr. Vincent Desjacques (Technion)

Link: https://youtu.be/FGxuXuwfF70

Resumo:

The gravitational field of a massive object moving in a discrete or continuous medium induces a density wake in that medium. Dynamical friction is the gravitational force exerted on the perturber as a result
of the induced density fluctuation. The pioneering study of Chandrasekhar (1943) considered a perturber linearly moving in a collisionless medium. In this talk, I will present an analytic approach to the dynamical friction acting on circularly moving point masses in a gaseous medium. I will show how it can be extended to axion dark matter backgrounds. Some astrophysical implications will also be discussed.