After a brief introduction to the black hole stability problem, we outline our recent proof of the linear stability of the non-extreme Kerr geometry.

We generalize the optical geometry to include, not only conformally static spacetimes, but any spacetime that admits a hypersurface orthogonal shearless congruence of worldlines. In the generalized optical geometry, which in general is time dependent, photons move with constant speed along spatial geodesics. Gyroscopes moving along spatial geodesics do not precess. We also classify inertial for...

We consider relativistic quantum field theory in the presence of an external electric potential a general curved space-time geometry. utilise Fermi coordinates adapted to time-like geodesic describe low-energy physics laboratory and calculate leading correction due curvature geometry Schr\"odinger equation. then compute non-vanishing probability excitation for hydrogen atom that falls or is sca...

We study the addition of an irrelevant operator to the N = 4 supersymmetric large N SU(N) gauge theory, in the presence of finite temperature, T . In the supergravity dual, the effect of the operator is known to correspond to a deformation of the AdS5 × S5 “throat” which restores the asymptotic ten dimensional Minkowski region of spacetime, completing the full D3–brane solution. The system at n...

The near-horizon geometry of the extremal four-dimensional Kerr black hole and certain generalizations thereof has an SL(2,R) × U(1) isometry group. Excitations around this geometry can be controlled by imposing appropriate boundary conditions. For certain boundary conditions, the U(1) isometry is enhanced to a Virasoro algebra. Here, we propose a free-field construction of this Virasoro algebra.

We give an example of a geometry in which two metallic objects in vacuum experience a repulsive Casimir force. The geometry consists of an elongated metal particle centered above a metal plate with a hole. We prove that this geometry has a repulsive regime using a symmetry argument and confirm it with numerical calculations for both perfect and realistic metals. The system does not support stab...