Speaker: Keiju Murata (Nihon University, Japan)
Title: Superradiant instability of Myers-Perry black strings
Abstract: We investigate the effect of superradiant scattering of gravitational perturbations on the stability of rotating black strings, focusing on the six dimensional equal-spinning Myers-Perry black string. We find that rapidly rotating black strings are unstable to gravitational superradiant modes within a bounded range of string lengths. The instability occurs because momentum along the string direction creates a potential barrier that allows for the confinement of superradiant modes. For some parameters, this instability competes with the Gregory-Laflamme instability, but otherwise exists independently. We also construct new family of black string solutions which brunch off from that of Myers-Perry black strings at the onset of instability.