Mode stability of a near-extremal Kerr superspinar

Understand

We study here the quasi-normal mode stability of a near-extremal Kerr superspinar, an exotic spinning compact object that exceeds the Kerr bound, under gravitational perturbations.

• Despite previous beliefs that these objects would be mode unstable, we show by analytically treating the Teukolsky equations that these objects are in fact mode stable under almost all (barring a zero-measure set) boundary conditions.