Marc Casals

Phenomenology of production and decay of spinning extra-dimensional black holes at hadron colliders

We present results of CHARYBDIS2, a new Monte Carlo simulation of black hole production and decay at hadron colliders in theories with large extra dimensions and TeV-scale gravity. The main new feature of CHARYBDIS2 is a full treatment of the spin-down phase of the decay process using the angular and energy distributions of the associated Hawking radiation. Also included are improved modelling of the loss of angular momentum and energy in the production process as well as a wider range of options for the Planck-scale termination of the decay. The new features allow us to study the effects of black hole spin and the feasibility of its observation in such theories. The code and documentation can be found at http://projects.hepforge.org/charybdis2/.

Brane decay of a (4+n)-dimensional rotating black hole: spin-0 particles

In this work, we study the ‘scalar channel’ of the emission of Hawking radiation from a (4+n)-dimensional, rotating black hole on the brane. We numerically solve both the radial and angular part of the equation of motion for the scalar field, and determine the exact values of the absorption probability and of the spheroidal harmonics, respectively. With these, we calculate the particle, energy and angular momentum emission rates, as well as the angular variation in the flux and power spectra – a distinctive feature of emission during the spin-down phase of the life of the produced black hole. Our analysis is free from any approximations, with our results being valid for arbitrarily large values of the energy of the emitted particle, angular momentum of the black hole and dimensionality of spacetime. We finally compute the total emissivities for the number of particles, energy and angular momentum and compare their relative behaviour for different values of the parameters of the theory.

Bulk Emission of Scalars by a Rotating Black Hole

We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. On the other hand, the proportion of the total (i.e., bulk+brane) power that is emitted into the bulk decreases monotonically with the angular momentum. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane.

Horizon instability of extremal Kerr black holes: Nonaxisymmetric modes and enhanced growth rate

We show that the horizon instability of the extremal Kerr black hole is associated with a singular branch point in the Green function at the superradiant bound frequency. We study generic initial data supported away from the horizon and find an enhanced growth rate due to nonaxisymmetric modes. The growth is controlled by the conformal weight

High frequency asymptotics for the spin-weighted spheroidal equation

h

Branch cut and quasinormal modes at large imaginary frequency in Schwarzschild space-time

of each mode. We speculate on connections to near-extremal black holes and holographic duality.

Analytic Investigation of the Branch Cut of the Green Function in Schwarzschild Space-time

We fully determine a uniformly valid asymptotic behavior for large, real

Self-Force and Green Function in Schwarzschild spacetime via Quasinormal Modes and Branch Cut

a\ensuremath{\omega}

Canonical quantization of the electromagnetic field on the Kerr background

and fixed

Quantization of fermions on Kerr space-time

m