Lecturer: Kfir Blum (WIS)
Abstract: Astrophysical and cosmological observations point to the existence of dark matter. However, its basic particle nature remains unknown. I will survey a program to look for hints to the particle nature of dark matter using minimal gravity alone, without assuming any direct interaction with ordinary matter. Within a few orders of magnitude from the boundaries of the currently allowed range for the mass of dark matter particles, gravitational dynamics produces distinctive signatures. At the lower mass end, gravity conspires with wave mechanics to yield a plethora of phenomena: dark matter condenses in galaxy centres, affecting the orbits of nearby stars; quenching dynamical friction on the motion of globular clusters; biasing cosmological inference from gravitational lensing of distant quasars; or producing unbound runaway stars. Each of these phenomena could yield the first positive smoking gun for the nature of dark matter, or, in case of null detection, provide model-independent limits that do not rely on unknown particle physics details.