Gravitational waves offer a unique window into black holes and their surrounding environments. This talk explores how black hole environments can imprint observable signatures on gravitational-wave signals. Topics include ultralight dark matter around black holes and turbulent accretion disks. Together, these examples show how gravitational-wave observations can probe and constrain ultralight dark matter, accretion physics, and strong-field gravity.

Inviter: Qing-Guo Huang