Interplay between Black Holes and Ultralight Dark Matter: Analytic Solutions

Understand

Dark matter (DM) can consist of a scalar field so light that DM particles in the galactic halo are best described by classical waves.

• We investigate how these classical solutions are influenced by the presence of a non-rotating supermassive black hole at the center of the galaxy, using an analytical, albeit approximate, approach.
• Relying on this analytic control, we examine the consequences of imposing causal boundary conditions at the horizon, which are typically overlooked.
• First, we examine the scenario where the backreaction of dark matter can be neglected.