6,461 research outputs found
A Dirichlet-type integral on spheres, applied to the fluid/gravity correspondence
We evaluate an analogue of an integral of Dirichlet over the sphere S^D, but
with an integrand that is independent of [(D + 1)/2] Killing coordinates. As an
application, we evaluate an integral that arises when comparing a conformal
fluid on S^D and black holes in (D + 2)-dimensional anti-de Sitter spacetime.Comment: 5 page
Higher-dimensional lifts of Killing-Yano forms with torsion
Using a Kaluza-Klein-type lift, it is shown how Killing-Yano forms with
torsion can remain symmetries of a higher-dimensional geometry, subject to an
algebraic condition between the Kaluza-Klein field strength and the
Killing-Yano form. The lift condition's significance is highlighted, and is
satisfied by examples of black holes in supergravity.Comment: 16 pages; v2: lift condition explicitly solve
Conformal isometry of the six-dimensional black string and dualities of null geodesics
We show that the extreme six-dimensional black string admits a conformal
isometry under inversion. Duality relations between null geodesics of various
brane geometries are demonstrated, some of which have a geometrical origin
through an optical metric.Comment: 9 pages. v2: references adde
Characterization of three-dimensional Lorentzian metrics that admit four Killing vectors
We consider three-dimensional Lorentzian metrics that locally admit four
independent Killing vectors. Their classification is summarized, and conditions
for characterizing them are found. These consist of algebraic classification of
the traceless Ricci tensor, and other conditions satisfied by the curvature and
its derivative.Comment: 15 page
Isolated poliovirus capsid protein VP1 induces a neutralizing response in rats
Antibodies were raised in rats against the poliovirus type 1 capsid proteins, VP1, VP2, and VP3. Antibodies directed against VP1 from type 1 poliovirus (Mahoney) neutralized type 1 but not type 2 poliovirus. Antibodies raised against VP2 and VP3 failed to neutralize type 1 virus. Thus, VP1 appears to be a neutralizing antigen for poliovirus and in its denatured form presents to the immune system its neutralizing determinants
Two-charge rotating black holes in four-dimensional gauged supergravity
We obtain an asymptotically AdS, non-extremal, electrically charged and
rotating black hole solution of 4-dimensional U(1)^4 gauged supergravity with 2
non-zero and independent U(1) charges. The thermodynamical quantities are
computed. We find BPS solutions that are nakedly singular. The solution is
generalized to include a NUT parameter and dyonic gauge fields. The string
frame metric has a rank-2 Killing-Stackel tensor and has completely integrable
geodesic motion, and the massless Klein-Gordon equation separates for the
Einstein frame metric.Comment: 15 pages; v2, v3: minor change
Black holes in N=8 supergravity from SO(4,4) hidden symmetries
We detail the construction of the most general asymptotically flat,
stationary, rotating, non-extremal, dyonic black hole of the four-dimensional
N=2 supergravity coupled to 3 vector multiplets that describes the STU model.
It generates through U-dualities the most general asymptotically flat,
stationary black hole of N=8 supergravity. We develop the solution generating
technique based on SO(4,4)/SL(2,R)^4 coset model symmetries, with an emphasis
on the 4-fold permutation symmetry of the gauge fields. We indicate how
previously known non-extremal and extremal solutions of the STU model are
recovered as limiting cases. Several properties of the general black hole
solution are discussed, including its thermodynamics, the quadratic mass
formula, the Bogomolny-Prasad-Sommerfield limit, the slow and fast extremal
rotating limits, its properties in regards to the Kerr/conformal field theory
correspondence, its Killing tensors and the separability of geodesic motion and
probe scalars.Comment: 63 pages; v2: minor changes, references added; v3: minor changes,
published version; v4: minor clarifications and typos fixed, Mathematica file
of solution include
Metric transformations under collapsing of Riemannian manifolds
Let (M,g) be a Riemannian manifold with an isometric action of the Lie group
G. Let g_G be a left invariant metric on G. Consider the diagonal G action on
the product with the metric g+g_G. In this paper we calculate the
formula for the metric h on the quotient space ; the map from
g to h is the metric transformation. In particular when g is the hyperbolic
metric on H^2 and G=S^1, the transformed metric h is Hamilton's cigar soliton
metric studied in the Ricci flow.Comment: 10 pages. This is a revised version with a new reference to previous
work of Cheege
Collapsing sequences of solutions to the Ricci flow on 3-manifolds with almost nonnegative curvature
We study sequences of 3-dimensional solutions to the Ricci flow with almost
nonnegative sectional curvatures and diameters tending to infinity. Such
sequences may arise from the limits of dilations about singularities of Type
IIb. In particular, we study the case when the sequence collapses, which may
occur when dilating about infinite time singularities. In this case we classify
the possible Gromov-Hausdorff limits and construct 2-dimensional virtual
limits. The virtual limits are constructed using Fukaya theory of the limits of
local covers. We then show that the virtual limit arising from appropriate
dilations of a Type IIb singularity is always Hamilton's cigar soliton
solution.Comment: 28 page
Seed for general rotating non-extremal black holes of N=8 supergravity
We describe the most general asymptotically flat, stationary, non-extremal,
dyonic black hole of the four-dimensional N = 2 supergravity coupled to 3
vector multiplets that describes the low-energy regime of the STU model. Under
U-dualities, this can be used as a seed to generate all single-centered
stationary black holes of N = 8 supergravity. The independent conserved charges
are the mass, angular momentum, four electric charges and four magnetic
charges; an independent NUT charge can also be added. Several aspects of the
black hole are presented, including thermodynamics, the BPS limit, the
near-horizon limit in the extremal fast and slow rotating cases, properties of
black hole horizons, the existence of Killing tensors and the separability of
probe scalars.Comment: BPS limit, extremal fast and slow rotating branches discussed. 1
Mathematica file of solution. Published versio
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