85 research outputs found
Blackfolds, Plane Waves and Minimal Surfaces
Minimal surfaces in Euclidean space provide examples of possible non-compact
horizon geometries and topologies in asymptotically flat space-time. On the
other hand, the existence of limiting surfaces in the space-time provides a
simple mechanism for making these configurations compact. Limiting surfaces
appear naturally in a given space-time by making minimal surfaces rotate but
they are also inherent to plane wave or de Sitter space-times in which case
minimal surfaces can be static and compact. We use the blackfold approach in
order to scan for possible black hole horizon geometries and topologies in
asymptotically flat, plane wave and de Sitter space-times. In the process we
uncover several new configurations, such as black helicoids and catenoids, some
of which have an asymptotically flat counterpart. In particular, we find that
the ultraspinning regime of singly-spinning Myers-Perry black holes, described
in terms of the simplest minimal surface (the plane), can be obtained as a
limit of a black helicoid, suggesting that these two families of black holes
are connected. We also show that minimal surfaces embedded in spheres rather
than Euclidean space can be used to construct static compact horizons in
asymptotically de Sitter space-times.Comment: v2: 67pp, 7figures, typos fixed, matches published versio
Born-Infeld particles and Dirichlet p-branes
Born-Infeld theory admits finite energy point particle solutions with
-function sources, BIons. I discuss their role in the theory of
Dirichlet -branes as the ends of strings intersecting the brane when the
effects of gravity are ignored. There are also topologically non-trivial
electrically neutral catenoidal solutions looking like two -branes joined by
a throat. The general solution is a non-singular deformation of the catenoid if
the charge is not too large and a singular deformation of the BIon solution for
charges above that limit. The intermediate solution is BPS and Coulomb-like.
Performing a duality rotation we obtain monopole solutions, the BPS limit being
a solution of the abelian Bogolmol'nyi equations. The situation closely
resembles that of sub and super extreme black-brane solutions of the
supergravity theories. I also show that certain special Lagrangian submanifolds
of , , may be regarded as supersymmetric configurations
consisting of -branes at angles joined by throats which are the sources of
global monopoles. Vortex solutions are also exhibited.Comment: 40 pages Latex file, no figure
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