8 research outputs found
On Black-Brane Instability In an Arbitrary Dimension
The black-hole black-string system is known to exhibit critical dimensions
and therefore it is interesting to vary the spacetime dimension , treating
it as a parameter of the system. We derive the large asymptotics of the
critical, i.e. marginally stable, string following an earlier numerical
analysis. For a background with an arbitrary compactification manifold we give
an expression for the critical mass of a corresponding black brane. This
expression is completely explicit for , the dimensional torus of
an arbitrary shape. An indication is given that by employing a higher
dimensional torus, rather than a single compact dimension, the total critical
dimension above which the nature of the black-brane black-hole phase transition
changes from sudden to smooth could be as low as .Comment: 1+14 pages, 2 eps figures. Replaced with the published versio
On non-uniform smeared black branes
We investigate charged dilatonic black -branes smeared on a transverse
circle. The system can be reduced to neutral vacuum black branes, and we
perform static perturbations for the reduced system to construct non-uniform
solutions. At each order a single master equation is derived, and the
Gregory-Laflamme critical wavelength is determined. Based on the non-uniform
solutions, we discuss thermodynamic properties of this system and argue that in
a microcanonical ensemble the non-uniform smeared branes are entropically
disfavored even near the extremality, if the spacetime dimension is , which is the critical dimension for the vacuum case. However, the critical
dimension is not universal. In a canonical ensemble the vacuum non-uniform
black branes are thermodynamically favorable at , whereas the
non-uniform smeared branes are favorable at near the extremality.Comment: 24 pages, 2 figures; v2: typos corrected, submitted to
Class.Quant.Gra
The Black Di-Ring: An Inverse Scattering Construction
We use the inverse scattering method (ISM) to derive concentric
non-supersymmetric black rings. The approach used here is fully
five-dimensional, and has the modest advantage that it generalizes readily to
the construction of more general axi-symmetric solutions.Comment: v3: 2 subsections added, typos fixed, more refs, journal version. v4:
a transcription error in the ADM mass fixe
Instabilities of Black Strings and Branes
We review recent progress on the instabilities of black strings and branes
both for pure Einstein gravity as well as supergravity theories which are
relevant for string theory. We focus mainly on Gregory-Laflamme instabilities.
In the first part of the review we provide a detailed discussion of the
classical gravitational instability of the neutral uniform black string in
higher dimensional gravity. The uniform black string is part of a larger phase
diagram of Kaluza-Klein black holes which will be discussed thoroughly. This
phase diagram exhibits many interesting features including new phases,
non-uniqueness and horizon-topology changing transitions. In the second part,
we turn to charged black branes in supergravity and show how the
Gregory-Laflamme instability of the neutral black string implies via a
boost/U-duality map similar instabilities for non- and near-extremal smeared
branes in string theory. We also comment on instabilities of D-brane bound
states. The connection between classical and thermodynamic stability, known as
the correlated stability conjecture, is also reviewed and illustrated with
examples. Finally, we examine the holographic implications of the
Gregory-Laflamme instability for a number of non-gravitational theories
including Yang-Mills theories and Little String Theory.Comment: 119 pages, 16 figures. Invited review for Classical and Quantum
Gravit
Charged Rotating Kaluza-Klein Black Holes Generated by G2(2) Transformation
Applying the G_{2(2)} generating technique for minimal D=5 supergravity to
the Rasheed black hole solution, we present a new rotating charged Kaluza-Klein
black hole solution to the five-dimensional Einstein-Maxwell-Chern-Simons
equations. At infinity, our solution behaves as a four-dimensional flat
spacetime with a compact extra dimension and hence describes a Kaluza-Klein
black hole. In particlar, the extreme solution is non-supersymmetric, which is
contrast to a static case. Our solution has the limits to the asymptotically
flat charged rotating black hole solution and a new charged rotating black
string solution.Comment: 24 page
Charged Black Holes in a Rotating Gross-Perry-Sorkin Monopole Background
We present a new class of stationary charged black hole solutions to
five-dimensional Einstein-Maxwell-Chern-Simons theories. We construct the
solutions by utilizing so called the squashing transformation. At infinity, our
solutions behave as a four-dimensional flat spacetime plus a `circle' and hence
describe a Kaluza-Klein black hole. More precisely, our solutions can be viewed
as a charged rotating black hole in a rotating Gross-Perry-Sorkin monopole
background with the black hole rotation induced from the background rotation.Comment: 25 pages, 6 figure
G2 Dualities in D=5 Supergravity and Black Strings
Five dimensional minimal supergravity dimensionally reduced on two commuting
Killing directions gives rise to a G2 coset model. The symmetry group of the
coset model can be used to generate new solutions by applying group
transformations on a seed solution. We show that on a general solution the
generators belonging to the Cartan and nilpotent subalgebras of G2 act as
scaling and gauge transformations, respectively. The remaining generators of G2
form a sl(2,R)+sl(2,R) subalgebra that can be used to generate non-trivial
charges. We use these generators to generalize the five dimensional Kerr string
in a number of ways. In particular, we construct the spinning electric and
spinning magnetic black strings of five dimensional minimal supergravity. We
analyze physical properties of these black strings and study their
thermodynamics. We also explore their relation to black rings.Comment: typos corrected (26 pages + appendices, 2 figures