Wade Naylor

Graviton emission from a higher-dimensional black hole

We discuss the graviton absorption probability (greybody factor) and the cross-section of a higher-dimensional Schwarzschild black hole (BH). We are motivated by the suggestion that a great many BHs may be produced at the LHC and bearing this fact in mind, for simplicity, we shall investigate the intermediate energy regime for a static Schwarzschild BH. That is, for (2M)1/(n?1)? ~ 1, where M is the mass of the black hole and ? is the energy of the emitted gravitons in (2+n)-dimensions. To find easily tractable solutions we work in the limit l >> 1, where l is the angular momentum quantum number of the graviton.

Quantum fluctuations on a thick de Sitter brane

Abstract We investigate quantum fluctuations on a de Sitter (dS) brane, which has its own thickness, in order to examine whether or not the finite thickness of the brane can act as a natural cut-off for the Kaluza–Klein (KK) spectrum. We calculate the amplitude of the KK modes and the bound state by using the zeta function method after a dimensional reduction. We show that the KK amplitude is finite for a given brane thickness and in the thin wall limit the standard surface divergent behavior is recovered. The strength of the divergence in the thin wall limit depends on the number of dimensions, e.g., logarithmic on a two-dimensional brane and quadratic on a four-dimensional brane. We also find that the amplitude of the bound state mode and KK modes depends on the choice of renormalization scale; and for fixed renormalization scales the bound state mode is insensitive to the brane thickness both for two- and four-dimensional dS branes.

Split fermion quasinormal modes

In this paper we use the conformal properties of the spinor field to show how we can obtain the fermion quasinormal modes for a higher-dimensional Schwarzschild black hole. These modes are of interest in so-called split fermion models, where quarks and leptons are required to exist on different branes in order to keep the proton stable. As has been previously shown, for brane-localized fields, the larger the number of dimensions the faster the black hole damping rate. Moreover, we also present the analytic forms of the quasinormal frequencies in both the large angular momentum and the large mode number limits.

Graviton emission from simply rotating Kerr―de Sitter black holes: Transverse traceless tensor graviton modes

In this article we present results for tensor graviton modes (in seven dimensions and greater,

Bulk dominated fermion emission on a Schwarzschild background

n\ensuremath{\ge}3

Fermion excitations of a tense brane black hole

) for gray-body factors of Kerr\char21{}de Sitter black holes and for Hawking radiation from simply rotating (

Can thick braneworlds be self-consistent?

n+4

Asymptotic iteration method for spheroidal harmonics of higher-dimensional Kerr-(A)dS black holes

)-dimensional Kerr black holes. Although there is some subtlety with defining the Hawking temperature of a Kerr\char21{}de Sitter black hole, we present some preliminary results for emissions assuming the standard Hawking normalization and a Bousso-Hawking-like normalization.

Volume stabilization in a warped flux compactification model

Using the WKBJ approximation and the Unruh method, we obtain semi-analytic expressions for the absorption probability (in all energy regimes) for Dirac fermions on a higher dimensional Schwarzschild background. We then present an analytic expression relating the absorption probability to the absorption cross section, and then use these results to plot the emission rates to third order in the WKBJ approximation. The setup we use is sufficiently general such that it could also easily be applied to any spherically symmetric background in

Reheating temperature and the right-handed neutrino mass

d