Area spectrum of rotating black holes via the new interpretation of quasinormal modes

Motivated by the recent work on a new physical interpretation of quasinormal modes by Maggiore, we utilize this new proposal to the interesting case of Kerr black hole. In particular, by modifying Hod's idea, the resulting black hole horizon area is quantized and the resulting area quantum is in full agreement with Bekenstein's result. Furthermore, in an attempt to show that the area spectrum is equally spaced, we follow Kunstatter's method. We propose a new interpretation as a result of Maggiore's idea, for the frequency that appears in the adiabatic invariant of a black hole. The derived area spectrum is similar to that of the quantum-corrected Kerr black hole but it is not equally spaced.Comment: v1: 4 pages, REVTeX, no figures; v2: clarifications and comments added, comments on last result modified, Abstract slightly changed; v3: comments and references added

The covariant, time-dependent Aharonov-Bohm Effect

We discuss two possible covariant generalizations of the Aharonov-Bohm effect - one expression in terms of the space-time line integral of the four-vector potential and the other expression in terms of the space-time "area" integral of the electric and magnetic fields written in terms of the Faraday 2-form. These expressions allow one to calculate the Aharonov-Bohm effect for time-dependent situations. In particular, we use these expressions to study the case of an infinite solenoid with a time varying flux and find that the phase shift is zero due to a cancellation of the Aharonov-Bohm phase shift with a phase shift coming from the Lorentz force associated with the electric field, ${\bf E} = - \partial_t {\bf A}$, outside the solenoid. This result may already have been confirmed experimentally.Comment: 11 pages, no figures, journal version, three added reference

Reply to "Comment on 'Universality of Quantum Gravity Corrections' "

We address the three points raised by the authors of the above Comment.Comment: 1 page, LaTeX, to appear in Phys.Rev.Lett

Regular black hole metrics and the weak energy condition

In this work we construct a family of spherically symmetric, static, charged regular black hole metrics in the context of Einstein-nonlinear electrodynamics theory. The construction of the charged regular black hole metrics is based on three requirements: (a) the weak energy condition should be satisfied, (b) the energy-momentum tensor should have the symmetry $T^{0}_{0}=T^{1}_{1}$, and (c) these metrics have to asymptotically behave as the Reissner-Nordstr\"{o}m black hole metric. In addition, these charged regular black hole metrics depend on two parameters which for specific values yield regular black hole metrics that already exist in the literature. Furthermore, by relaxing the third requirement, we construct more general regular black hole metrics which do not behave asymptotically as a Reissner-Nordstr\"{o}m black hole metric.Comment: v1: 11 pages, LaTeX, no figures; v2: typos corrected and one reference removed to match published version in Phys. Lett.

CM cycles on Kuga–Sato varieties over Shimura curves and Selmer groups

Given a modular form f of even weight larger than two and an imaginary quadratic field K satisfying a relaxed Heegner hypothesis, we construct a collection of CM cycles on a Kuga–Sato variety over a suitable Shimura curve which gives rise to a system of Galois cohomology classes attached to f enjoying the compatibility properties of an Euler system. Then we use Kolyvagin’s method [21], as adapted by Nekova´¿r [28] to higher weight modular forms, to bound the size of the relevant Selmer group associated to f and K and prove the finiteness of the (primary part) of the Shafarevich–Tate group, provided that a suitable cohomology class does not vanish.Peer ReviewedPostprint (author's final draft

Quantum aether and an invariant Planck scale

We argue that a quantum aether is consistent with the principle of relativity and can provide an economical way of having an invariant quantum gravity or Planck scale. We also show that it may change the effective scale at which quantum gravity effects may be observable.Comment: 3 pages, LaTeX, no figures, to appear in EP

Black holes with constant topological Euler density

A class of four dimensional spherically symmetric and static geometries with constant topological Euler density is studied. These geometries are shown to solve the coupled Einstein-Maxwell system when non-linear Born-Infeld-like electrodynamics is employed.Comment: 7 pages, REVTeX 4, 1 figure, to appear in EP