454 research outputs found

### The Thermodynamics of Kaluza-Klein Black Hole/Bubble Chains

A Killing bubble is a minimal surface that arises as the fixed surface of a
spacelike Killing field. We compute the bubble contributions to the Smarr
relations and the mass and tension first laws for spacetimes containing both
black holes and Killing bubbles. The resulting relations display an interesting
interchange symmetry between the properties of black hole horizons and those of
KK bubbles. This interchange symmetry reflects the underlying relation between
static bubbles and black holes under double analytic continuation of the time
and Kaluza-Klein directions. The thermodynamics of bubbles involve a
geometrical quantity that we call the bubble surface gravity, which we show has
several properties in common with the black hole surface gravity.Comment: 20 pages, 1 figur

### Komar Integrals in Higher (and Lower) Derivative Gravity

The Komar integral relation of Einstein gravity is generalized to Lovelock
theories of gravity. This includes, in particular, a new boundary integral for
the Komar mass in Einstein gravity with a nonzero cosmological constant, which
has a finite result for asymptotically AdS black holes, without the need for an
infinite background subtraction. Explicit computations of the Komar mass are
given for black holes in pure Lovelock gravities of all orders and in general
Gauss-Bonnet theories.Comment: 16 pages; v2 - references and comment on relation to Noether charge
method adde

### Tension term, interchange symmetry, and the analogy of energy and tension laws of the AdS soliton solution

In this paper, we reconsider the energy and tension laws of the Ricci flat
black hole by taking the contribution of the tension term into account. After
this considering and inspired by the interchange symmetry between the Ricci
flat black hole and the AdS soliton solution which arises from the double
analytic continuation of the time and compact spatial direction, we find out
the analogy of the energy and tension laws of the AdS soliton solution.
Moreover, we also investigate the energy and tension laws of the boosted Ricci
flat black hole, and discuss the boosted AdS soliton solution. However,
although there is the same interchange symmetry between the boosted Ricci flat
black hole and boosted AdS soliton, the analogy of laws of the boosted AdS
soliton solution may be of no sense for the existence of the closed timelike
curves and conical singularity. In spite of that, the conserved charges such as
the energy and momentum of the boosted AdS soliton are well-defined, and an
interesting result is that its energy is lower than that of the static AdS
soliton. On the other hand, note that although the laws obtained above are the
same as those of the asymptotically flat case, the underlying deduced contents
are different. Thus, our results could also be considered as a simple
generalization to the asymptotically AdS case. Moreover, during the
calculation, we find that there may be a new way to define the gravitational
tension which can come from the quasi-local stress tensor of the counter-term
method.Comment: V4: 15 pages, no figure, version to appear in JHE

### Vacuum solutions with nontrivial boundaries for the Einstein-Gauss-Bonnet theory

The classification of certain class of static solutions for the
Einstein-Gauss-Bonnet theory in vacuum is presented. The spacelike section of
the class of metrics under consideration is a warped product of the real line
with a nontrivial base manifold. For arbitrary values of the Gauss-Bonnet
coupling, the base manifold must be Einstein with an additional scalar
restriction. The geometry of the boundary can be relaxed only when the
Gauss-Bonnet coupling is related with the cosmological and Newton constants, so
that the theory admits a unique maximally symmetric solution. This additional
freedom in the boundary metric allows the existence of three main branches of
geometries in the bulk, containing new black holes and wormholes in vacuum.Comment: Prepared for the proceedings of the 7th Alexander Friedmann
International Seminar on Gravitation and Cosmology, July 2008, Joao Pessoa,
Brasil. 4 pages, References adde

### Do Killing-Yano tensors form a Lie Algebra?

Killing-Yano tensors are natural generalizations of Killing vectors. We
investigate whether Killing-Yano tensors form a graded Lie algebra with respect
to the Schouten-Nijenhuis bracket. We find that this proposition does not hold
in general, but that it does hold for constant curvature spacetimes. We also
show that Minkowski and (anti)-deSitter spacetimes have the maximal number of
Killing-Yano tensors of each rank and that the algebras of these tensors under
the SN bracket are relatively simple extensions of the Poincare and (A)dS
symmetry algebras.Comment: 17 page

### The First Law for Boosted Kaluza-Klein Black Holes

We study the thermodynamics of Kaluza-Klein black holes with momentum along
the compact dimension, but vanishing angular momentum. These black holes are
stationary, but non-rotating. We derive the first law for these spacetimes and
find that the parameter conjugate to variations in the length of the compact
direction is an effective tension, which generally differs from the ADM
tension. For the boosted black string, this effective tension is always
positive, while the ADM tension is negative for large boost parameter. We also
derive two Smarr formulas, one that follows from time translation invariance,
and a second one that holds only in the case of exact translation symmetry in
the compact dimension. Finally, we show that the `tension first law' derived by
Traschen and Fox in the static case has the form of a thermodynamic Gibbs-Duhem
relation and give its extension in the stationary, non-rotating case.Comment: 20 pages, 0 figures; v2 - reference adde

### Dilaton Black Holes in de Sitter or Anti-de Sitter Universe

Poletti and Wiltshire have shown that, with the exception of a pure
cosmological constant, the solution of a dilaton black hole in the background
of de Sitter or anti-de Sitter universe, does not exist in the presence of one
Liouville-type dilaton potential. Here with the combination of three
Liouville-type dilaton potentials, we obtain the dilaton black hole solutions
in the background of de Sitter or anti-de Sitter universe.Comment: 13 pages,to appear in Phys. Rev.

### A Probe Particle in Kerr-Newman-deSitter Cosmos

We consider the force acting on a spinning charged test particle (probe
particle) with the mass m and the charge q in slow rotating the
Kerr-Newman-deSitter(KNdS) black hole with the mass M and the charge Q. We
consider the case which the spin vector of the probe particle is parallel to
the angular momentum vector of the KNdS space-time. We take account of the
gravitational spin-spin interaction under the slow rotating limit of the KNdS
space-time. When Q=M and q=m, we show that the force balance holds including
the spin-spin interaction and the motion is approximately same as that of a
particle in the deSitter space-time. This force cancellation suggests the
possibility of the existence of an exact solution of spinning multi-KNdS black
hole.Comment: 7 pages, Classical and Quantum Gravity accepte

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