123 research outputs found
Algebraically special solutions in AdS/CFT
We investigate the AdS/CFT interpretation of the class of algebraically
special solutions of Einstein gravity with a negative cosmological constant.
Such solutions describe a CFT living in a 2+1 dimensional time-dependent
geometry that, generically, has no isometries. The algebraically special
condition implies that the expectation value of the CFT energy-momentum tensor
is a local function of the boundary metric. When such a spacetime is slowly
varying, the fluid/gravity approximation is valid and one can read off the
values of certain higher order transport coefficients. To do this, we introduce
a formalism for studying conformal, relativistic fluids in 2+1 dimensions that
reduces everything to the manipulation of scalar quantities.Comment: 30 pages + appendices, 2 figures; v2: typos corrected, ref. adde
Algebraically special perturbations of the Schwarzschild solution in higher dimensions
We study algebraically special perturbations of a generalized Schwarzschild
solution in any number of dimensions. There are two motivations. First, to
learn whether there exist interesting higher-dimensional algebraically special
solutions beyond the known ones. Second, algebraically special perturbations
present an obstruction to the unique reconstruction of general metric
perturbations from gauge-invariant variables analogous to the Teukolsky scalars
and it is desirable to know the extent of this non-uniqueness. In four
dimensions, our results generalize those of Couch and Newman, who found
infinite families of time-dependent algebraically special perturbations. In
higher dimensions, we find that the only regular algebraically special
perturbations are those corresponding to deformations within the Myers-Perry
family. Our results are relevant for several inequivalent definitions of
"algebraically special".Comment: 23 pages, no figures. v2: references added; discussion improved;
matches published versio
A supersymmetric black ring
A new supersymmetric black hole solution of five-dimensional supergravity is
presented. It has an event horizon of topology S1xS2. This is the first example
of a supersymmetric, asymptotically flat black hole of non-spherical topology.
The solution is uniquely specified by its electric charge and two independent
angular momenta. These conserved charges can be arbitrarily close, but not
exactly equal, to those of a supersymmetric black hole of spherical topology.Comment: 4 pages, 1 figure. v2: Comment about chiral null models remove
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