Speaker : N. Warburton

Title : Inspiral into Gargantua : gravitational waves from near-extremal black holes

Abstract : We model the inspiral of a compact object into a more massive black hole rotating very near the theoretical maximum. We find that once the body enters the near-horizon regime the gravitational radiation is characterized by a constant frequency, equal to (twice) the horizon frequency, with an exponentially damped profile. This contrasts with the usual "chirping" behavior and, if detected, would constitute a "smoking gun" for a near-extremal black hole in nature. We also present preliminary high-spin results in the conservative sector for the shift in the location of the inner-most stable circular orbit (ISCO).