Speaker
Description
Abstract: Scalar field dark matter could provide a unified framework to describe galactic halos. In this talk, we present two complementary approaches based on self-gravitating scalar field solutions. First, we study ℓ-boson stars as dark matter halos and infer their parameters using observed rotation curves. Second, motivated by the presence of supermassive black holes at the centers of galaxies, we analyze how scalar field dark matter halos are modified by the inclusion of a central black hole. We construct gravitational atoms from solutions of the Einstein–Klein–Gordon equations, describing scalar field configurations that extend from the black hole vicinity to the outer halo region. We find that the presence of a black hole produces only a mild density enhancement near the horizon, in contrast with the sharp spikes expected for cold dark matter. Together, these results show how scalar field models can describe galactic dark matter halos across a broad range of scales.