Asymptotic Quasinormal Frequencies of d-dimensional Schwarzschild Black Holes

We determine the quasinormal frequencies for all gravitational perturbations of the d-dimensional Schwarzschild black hole, in the infinite damping limit. Using the potentials for gravitational perturbations derived recently by Ishibashi and Kodama, we show that in all cases the asymptotic real part of the frequency is proportional to the Hawking temperature with a coefficient of log 3. Via the correspondence principle, this leads directly to an equally spaced entropy spectrum. We comment on the possible implications for the spacing of eigenvalues of the Virasoro generator in the associated near-horizon conformal algebra.Comment: 8 pages, Latex, v2: Additional references, minor change

Universality of Highly Damped Quasinormal Modes for Single Horizon Black Holes

It has been suggested that the highly damped quasinormal modes of black holes provide information about the microscopic quantum gravitational states underlying black hole entropy. This interpretation requires the form of the highly damped quasinormal mode frequency to be universally of the form: $\hbar\omega_R = \ln(l)kT_{BH}$, where $l$ is an integer, and $T_{BH}$ is the black hole temperature. We summarize the results of an analysis of the highly damped quasinormal modes for a large class of single horizon, asymptotically flat black holes.Comment: 9 pages, 1 figure, submitted to the proceedings of Theory CANADA 1, which will be published in a special edition of the Canadian Journal of Physic

Mirror symmetry and the flavor vortex operator in two dimensions

The flavor vortex operator $V_\alpha$ is a local disorder operator defined by coupling a two-dimensional $\mathcal{N}=(2,2)$ chiral multiplet to a non-dynamical gauge field with vortex singularity of holonomy $2\pi\alpha$. We show that it is related to the mirror-dual twisted chiral multiplet, with bottom component $y$, as $V_\alpha=e^{-\alpha y}$.Comment: 6 page

Orientifolding in N=2 Superspace

We discuss orientifold projections on superspace effective actions for hypermultiplets. We present a simple and new mechanism that allows one to find the Kahler potential and complex structure for the N=1 theory directly in terms of the parent N=2 theory. As an application, we demonstrate our method for Calabi-Yau orientifold compactifications of type IIB superstrings.Comment: 7 page

Supersymmetric SO(N_c) Gauge Theory and Matrix Model

By applying the method of Dijkgraaf-Vafa, we study matrix model related to supersymmetric SO(N_c) gauge theory with N_f flavors of quarks in the vector representation found by Intriligator-Seiberg. By performing the matrix integral over tree level superpotential characterized by light meson fields (mass deformation) in electric theory, we reproduce the exact effective superpotential in the gauge theory side. Moreover, we do similar analysis in magnetic theory. It turns out the matrix descriptions of both electric and magnetic theories are the same: Seiberg duality in the gauge theory side.Comment: 9 pp:v2 Kept N_c for gauge theory and N for matrix model and modified the measure of matrix integral with the footnote and to appear in PL

The Mystery of the Asymptotic Quasinormal Modes of Gauss-Bonnet Black Holes

We analyze the quasinormal modes of $D$-dimensional Schwarzschild black holes with the Gauss-Bonnet correction in the large damping limit and show that standard analytic techniques cannot be applied in a straightforward manner to the case of infinite damping. However, by using a combination of analytic and numeric techniques we are able to calculate the quasinormal mode frequencies in a range where the damping is large but finite. We show that for this damping region the famous $\ln(3)$ appears in the real part of the quasinormal mode frequency. In our calculations, the Gauss-Bonnet coupling, $\alpha$, is taken to be much smaller than the parameter $\mu$, which is related to the black hole mass.Comment: 12 pages and 5 figure