Speaker
Description
In recent years, black hole superradiance, extraction of energy and angular momentum from a rotating black hole, has attracted considerable attention as a probe of light bosonic particles.
For a massive bosonic field, superradiance can lead to an instability and the growth of a macroscopic boson cloud, which may subsequently emit gravitational waves.
The cloud is often said to be seeded by vacuum fluctuations, which are amplified by the superradiant instability into a macroscopically occupied state.
Nevertheless, the instability is usually described using a classical field, leaving unclear how this quantum growth gives rise to the classical cloud and whether any quantum signatures remain observable.
In this talk, I will discuss the quantization of a massive scalar field around a rotating black hole and its quantum evolution.
I will then explain how gravitational wave emission induces decoherence, providing a route from the initial quantum fluctuations to a classical boson cloud.