1,747 research outputs found
Black rings in more than five dimensions
We construct balanced black ring solutions in spacetime dimensions,
by solving the Einstein field equations numerically with suitable boundary
conditions. The black ring solutions have a regular event horizon with
topology, and they approach the Minkowski background
asymptotically. We analyze their global and horizon properties. The Smarr
formula is well satisfied.Comment: 8 pages, 3 figure
Multi-black rings and the phase diagram of higher-dimensional black holes
Configurations of multiple concentric black rings play an important role in
determining the pattern of branchings, connections and mergers between
different phases of higher-dimensional black holes. We examine them using both
approximate and (in five dimensions) exact methods. By identifying the role of
the different scales in the system, we argue that it is possible to have
multiple black ring configurations in which all the rings have equal
temperature and angular velocity. This allows us to correct and improve in a
simple, natural manner, an earlier proposal for the phase diagram of
singly-rotating black holes in .Comment: 14 pages, 2 figure
Braneworlds and Dark Energy
In the Randall-Sundrum scenario, we analyse the dynamics of an AdS5
braneworld when conformal matter fields propagate in five dimensions. We show
that conformal fields of weight -4 are associated with stable geometries which
describe the dynamics of inhomogeneous dust, generalized dark radiation and
homogeneous polytropic dark energy on a spherically symmetric 3-brane embedded
in the compact AdS5 orbifold. We discuss aspects of the radion stability
conditions and of the localization of gravity in the vicinity of the brane.Comment: 12 pages, latex, 3 eps figures. Talk given at the Seventh Workshop on
Quantum Field Theory under the Influence of External Conditions, IEEC, CSIC
and University of Barcelona, Barcelona, Catalonia, Spain, 5-9 September 2005.
Revised version published in the workshop proceedings, J. Phys. A:
Mathematical and General. Typos corrected and some changes introduced for
clarit
Derivation of the blackfold effective theory
We study fluctuations and deformations of black branes over length scales
larger than the horizon radius. We prove that the Einstein equations for the
perturbed p-brane yield, as constraints, the equations of the effective
blackfold theory. We solve the Einstein equations for the perturbed geometry
and show that it remains regular on and outside the black brane horizon. This
study provides an ab initio derivation of the blackfold effective theory and
gives explicit expressions for the metrics near the new black holes and black
branes that result from it, to leading order in a derivative expansion.Comment: 20 pages. v4: Typo corrected in eq. (6.11) -- erratum in the
published versio
Born-Infeld Strings Tunneling to D-branes
Recent work on solutions to the Born-Infeld theory used to describe D-branes
suggests that fundamental strings can be viewed, in a certain limit, as
D-branes whose worldvolumes have collapsed to string-like configurations. Here
we address the possibility of undoing this collapse, by inducing the string to
tunnel to an extended brane configuration. Using semiclassical methods we argue
that, by putting one of these Born-Infeld strings in the background of a
uniform 4-form RR field strength, the string can nucleate a spheroidal bulge of
D2-brane, or, if the string is wrapped around a small enough circle, it can
tunnel to a toroidal D2-brane. This process can also be interpreted in terms of
the M2-brane. We also address the extension to other D-branes, and discuss
the range of validity of the approximations involved.Comment: 13 pages, 2 figure
static black holes with event horizon topology
We present numerical evidence for the existence of new black hole solutions
in spacetime dimensions. They approach asymptotically the Minkowski
background and have an event horizon topology . These static
solutions share the basic properties of the nonrotating black rings in five
dimensions, in particular the presence of a conical singularity.Comment: 10 pages, 4 figure
Black Hole Production at a TeV
In this talk I briefly discuss some features of a striking signature of TeV
quantum gravity/strings and large extra dimensions: the production of exotic
objects such as black holes, and their stringy precursors, the string
resonances at large masses which can be dubbed `string balls'. The focus is on
aspects less frequently discussed in other reviews of this subject.Comment: 6 pages. Invited talk at the 12th Workshop on General Relativity and
Gravitation, Tokyo, November 25-28, 200
Cutoff AdS/CFT duality and the quest for braneworld black holes
We present significant evidence in favour of the holographic conjecture that
``4D black holes localized on the brane found by solving the classical bulk
equations in are quantum corrected black holes and not classical
ones''. The crucial test is the calculation of the quantum correction to the
Newtonian potential based on a numerical computation of in
Schwarzschild spacetime for matter fields in the zero temperature Boulware
vacuum state. For the case of the conformally invariant scalar field the
leading order term is found to be $M/45\pi r^3$. This result is equivalent to
the result which was previously obtained in the weak-field approximation using
Feynman diagrams and which has been shown to be equivalent, via the AdS/CFT
duality, to the analogous calculation in Randall-Sundrum braneworlds. This
asymptotic behavior was not captured in the analytical approximations for
proposed in the literature. The 4D backreaction equations are then
used to make a prediction about the existence and the possible spacetime
structure of macroscopic static braneworld black holes.Comment: 4 pages, 2 figure
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