403 research outputs found
On black holes in multidimensional theory with Ricci-flat internal spaces
A generalization of the Tangherlini solution for the case of n internal
Ricci-flat spaces is obtained. It is shown that in the (2+d)-dimensional
section a horizon exists only in the trivial case when the internal-space
factors are constant. The p-adic analog of the solution is also considered.Comment: 6 pages, Late
Brane/Flux Annihilation and the String Dual of a Non-Supersymmetric Field Theory
We consider the dynamics of p anti-D3 branes inside the Klebanov-Strassler
geometry, the deformed conifold with M units of RR 3-form flux around the S^3.
We find that for p<<M the system relaxes to a nonsupersymmetric NS 5-brane
``giant graviton'' configuration, which is classically stable, but quantum
mechanically can tunnel to a nearby supersymmetric vacuum with M-p D3 branes.
This decay mode is exponentially suppressed and proceeds via the nucleation of
an NS 5-brane bubble wall. We propose a dual field theory interpretation of the
decay as the transition between a nonsupersymmetric ``baryonic'' branch and a
supersymmetric ``mesonic'' branch of the corresponding SU(2M-p)x SU(M-p) low
energy gauge theory. The NS 5-brane tunneling process also provides a simple
explanation of the geometric transition by which D3-branes can dissolve into
3-form flux.Comment: 27 pages, 4 figures, typo correcte
Randall-Sundrum black holes and strange stars
It has recently been suggested that the existence of bare strange stars is
incompatible with low scale gravity scenarios. It has been claimed that in such
models, high energy neutrinos incident on the surface of a bare strange star
would lead to catastrophic black hole growth. We point out that for the flat
large extra dimensional case, the parts of parameter space which give rise to
such growth are ruled out by other methods. We then go on to show in detail how
black holes evolve in the the Randall-Sundrum two brane scenario where the
extra dimensions are curved. We find that catastrophic black hole growth does
not occur in this situation either. We also present some general expressions
for the growth of five dimensional black holes in dense media.Comment: 16 pages, more numerics has lead to different path to same
conclusion. Accepted in PR
Caged Black Holes: Black Holes in Compactified Spacetimes I -- Theory
In backgrounds with compact dimensions there may exist several phases of
black objects including the black-hole and the black-string. The phase
transition between them raises puzzles and touches fundamental issues such as
topology change, uniqueness and Cosmic Censorship. No analytic solution is
known for the black hole, and moreover, one can expect approximate solutions
only for very small black holes, while the phase transition physics happens
when the black hole is large. Hence we turn to numerical solutions. Here some
theoretical background to the numerical analysis is given, while the results
will appear in a forthcoming paper. Goals for a numerical analysis are set. The
scalar charge and tension along the compact dimension are defined and used as
improved order parameters which put both the black hole and the black string at
finite values on the phase diagram. Predictions for small black holes are
presented. The differential and the integrated forms of the first law are
derived, and the latter (Smarr's formula) can be used to estimate the ``overall
numerical error''. Field asymptotics and expressions for physical quantities in
terms of the numerical ones are supplied. Techniques include ``method of
equivalent charges'', free energy, dimensional reduction, and analytic
perturbation for small black holes.Comment: 23 pages. v3: version to be published in PRD, 3 references adde
Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics
We propose an interesting scheme for distributed orbital state quantum
cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic
ensembles which consist of identical three-level atoms are trapped in distant
cavities connected by a single-mode integrated optical star coupler. These
qubits can be manipulated through appropriate modulation of the coupling
constants between atomic ensemble and classical field, and the cavity decay can
be largely suppressed as the number of atoms in the ensemble qubits increases.
The fidelity of each cloned qubit can be obtained with analytic result. The
present scheme provides a new way to construct the quantum communication
network.Comment: 5 pages, 4 figure
Myers' type theorems and some related oscillation results
In this paper we study the behavior of solutions of a second order
differential equation. The existence of a zero and its localization allow us to
get some compactness results. In particular we obtain a Myers' type theorem
even in the presence of an amount of negative curvature. The technique we use
also applies to the study of spectral properties of Schroedinger operators on
complete manifolds.Comment: 16 page
The Fall of Stringy de Sitter
Kachru, Kallosh, Linde, & Trivedi recently constructed a four-dimensional de
Sitter compactification of IIB string theory, which they showed to be
metastable in agreement with general arguments about de Sitter spacetimes in
quantum gravity. In this paper, we describe how discrete flux choices lead to a
closely-spaced set of vacua and explore various decay channels. We find that in
many situations NS5-brane meditated decays which exchange NSNS 3-form flux for
D3-branes are comparatively very fast.Comment: 35 pp (11 pp appendices), 5 figures, v3. fixed minor typo
A boundary value problem for the five-dimensional stationary rotating black holes
We study the boundary value problem for the stationary rotating black hole
solutions to the five-dimensional vacuum Einstein equation. Assuming the two
commuting rotational symmetry and the sphericity of the horizon topology, we
show that the black hole is uniquely characterized by the mass, and a pair of
the angular momenta.Comment: 16 pages, no figure
Uniqueness Theorem for Generalized Maxwell Electric and Magnetic Black Holes in Higher Dimensions
Based on the conformal energy theorem we prove the uniqueness theorem for
static higher dimensional electrically and magnetically charged black holes
being the solution of Einstein (n-2)-gauge forms equations of motion. Black
hole spacetime contains an asymptotically flat spacelike hypersurface with
compact interior and non-degenerate components of the event horizon.Comment: 7 pages, RevTex, to be published in Phys.Rev.D1
Quasi Stable Black Holes at the Large Hadron Collider
We adress the production of black holes at LHC and their time evolution in
space times with compactified space like extra dimensions. It is shown that
black holes with life times of hundred fm/c can be produced at LHC. The
possibility of quasi-stable remnants is discussed.Comment: 4 pages, 3 figures, typos removed, omitted factors included, accepted
for publicatio
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