As we mentioned earlier, gravitational radiation from black hole oscillations exhibits certain characteristic frequencies which are independent of the processes giving rise to these oscillations. These ``quasi-normal'' frequencies are directly connected to the parameters of the black hole (mass, charge and angular momentum) and for stellar mass black holes are expected to be inside the bandwidth of the constructed gravitational wave detectors.
The perturbations of a Schwarzschild black hole reduce to a
simple wave equation which has been studied extensively. The wave
equation for the case of a Reissner-Nordström black hole is more
or less similar to the Schwarzschild case, but for Kerr one has
to solve a system of coupled wave equations (one for the radial
part and one for the angular part). For this reason the Kerr case
has been studied less thoroughly. Finally, in the case of
Kerr-Newman black holes we face the problem that the
perturbations cannot be separated in their angular and radial
parts and thus apart from special cases [124] the problem has not been studied at all.
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Quasi-Normal Modes of Stars and Black Holes
Kostas D. Kokkotas and Bernd G. Schmidt http://www.livingreviews.org/lrr-1999-2 © Max-Planck-Gesellschaft. ISSN 1433-8351 Problems/Comments to livrev@aei-potsdam.mpg.de |