Daniela Doneva (Eberhard-Karls-Universitat Tuebingen,Germany)
"Black hole quasi-normal mode ringdown"

Quasinormal modes of black holes encode characteristics of the underlying theory of gravity and the back hole environment. By accurately observing a large number of them one should be able to solve the inverse problem and constrain the underlying theoretical models. There are two important obstacles, though. The first one is the difficulty in quasinormal mode calculations especially for rotating black holes where no separation of variables is possible. The second one is that the ringdown, following a binary merger, will have a relatively low signal-to-noise ratio even for the next generation of gravitational wave detectors. The extracted mode frequencies will also be contaminated by nonlinearities from the actual merger. Recent developments in this topic, including possible approaches to mitigate these obstacles, will be discussed in the present talk.