18,696 research outputs found
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,
, outside the solenoid. This result may already
have been confirmed experimentally.Comment: 11 pages, no figures, journal version, three added reference
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
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 , 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.
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
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