6,019 research outputs found
Pure geometric thick -branes: stability and localization of gravity
We study two exactly solvable five-dimensional thick brane world models in
pure metric gravity. Working in the Einstein frame, we show that these
solutions are stable against small linear perturbations, including the tensor,
vector, and scalar modes. For both models, the corresponding gravitational zero
mode is localized on the brane, which leads to the four-dimensional Newton's
law; while the massive modes are nonlocalized and only contribute a small
correction to the Newton's law at a large distance.Comment: 7 pages, 2 figures, improved version, accepted by Eur. Phys. J.
-field kinks: stability, exact solutions and new features
We study a class of noncanonical real scalar field models in
-dimensional flat space-time. We first derive the general criterion for
the classical linear stability of an arbitrary static soliton solution of these
models. Then we construct first-order formalisms for some typical models and
derive the corresponding kink solutions. The linear structures of these
solutions are also qualitatively analyzed and compared with the canonical kink
solutions.Comment: 14 pages, 3 figure
gauge vector field on a codimension-2 brane
In this paper, we obtain a gauge invariant effective action for a bulk
massless gauge vector field on a brane with codimension two by using a
general Kaluza-Klein (KK) decomposition for the field. It suggests that there
exist two types of scalar KK modes to keep the gauge invariance of the action
for the massive vector KK modes. Both the vector and scalar KK modes can be
massive. The masses of the vector KK modes contain two parts,
and , due to the existence of the two extra
dimensions. The masses of the two types of scalar KK modes and
are related to the vector ones, i.e.,
and . Moreover, we
derive two Schr\"{o}dinger-like equations for the vector KK modes, for which
the effective potentials are just the functions of the warp factor.Comment: 15 pages,no figures, accepted by JHE
Entropy/Area spectra of the charged black hole from quasinormal modes
With the new physical interpretation of quasinormal modes proposed by
Maggiore, the quantum area spectra of black holes have been investigated
recently. Adopting the modified Hod's treatment, results show that the area
spectra for black holes are equally spaced and the spacings are in a unified
form, , in Einstein gravity. On the other hand,
following Kunstatter's method, the studies show that the area spectrum for a
nonrotating black hole with no charge is equidistant. And for a rotating (or
charged) black hole, it is also equidistant and independent of the angular
momentum (or charge ) when the black hole is far from the extremal case.
In this paper, we mainly deal with the area spectrum of the stringy charged
Garfinkle-Horowitz-Strominger black hole, originating from effective action
that emerges in the low-energy string theory. We find that both methods give
the same results-that the area spectrum is equally spaced and does not depend
on the charge . Our study may provide new insights into understanding the
area spectrum and entropy spectrum for stringy black holes.Comment: 13 pages, no figure
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