Gyroscope precession as an indicator of a Kerr horizons

by Mr Prashant Kocherlakota (DAA - TIFR)

Tuesday 14 Mar 2017, 16:00 → 17:00 Asia/Kolkata

A269 (DAA SEMINAR ROOM)

The spin of a gyroscope when placed in a rotating spacetime undergoes precession, due to frame-dragging. The Kerr solution, which is one such rotating spacetime, describes a rotating black hole or a naked singularity, depending on the dimensionless angular momentum parameter. In this talk I will discuss how, for a class of observers, these precession frequencies diverge on the event horizon of a black hole but are finite and regular for a naked singularity, everywhere except at the singularity itself. Although the precession frequency diverges in both cases, I will show that they have characteristic features that can be used to tell them apart. These are coordinate-invariant effects and therefore can be interpreted as a genuine test of the existence of an event horizon.