262 research outputs found
Universal Kaluza-Klein reductions of type IIB to N=4 supergravity in five dimensions
We construct explicit consistent Kaluza-Klein reductions of type IIB
supergravity on HK_4 x S^1, where HK_4 is an arbitrary four-dimensional
hyper-Kaehler manifold, and on SE5, an arbitrary five-dimensional
Sasaki-Einstein manifold. In the former case we obtain the bosonic action of
D=5 N=4 (ungauged) supergravity coupled to two vector multiplets. For the SE_5
case we extend a known reduction, which leads to minimal D=5 N=2 gauged
supergravity, to also include a multiplet of massive fields, containing the
breathing mode of the SE_5. We show that the resulting D=5 action is also
consistent with N=4 gauged supergravity coupled to two vector multiplets. This
theory has a supersymmetric AdS_5 vacuum, which uplifts to the class of
supersymmetric AdS_5 x SE_5 solutions, that spontaneously breaks N=4 to N=2,
and also a non-supersymmetric AdS_5 vacuum which uplifts to a class of
solutions first found by Romans.Comment: 1+34 pages. v2: Minor typos corrected, three references added.
Version to be published in JHE
Concentric Black Rings
We present new supersymmetric solutions of five-dimensional minimal
supergravity that describe concentric black rings with an optional black hole
at the common centre. Configurations of two black rings are found which have
the same conserved charges as a single rotating black hole; these black rings
can have a total horizon area less than, equal to, or greater than the black
hole with the same charges. A numerical investigation of these particular black
ring solutions suggests that they do not have closed timelike curves.Comment: 7 pages, minor alterations, typos corrected. Version to be published
in PR
Universal fermionic spectral functions from string theory
We carry out the first holographic calculation of a fermionic response
function for a strongly coupled system with an explicit D=10 or D=11
supergravity dual. By considering the supersymmetry current, we obtain a
universal result applicable to all d=3 N=2 SCFTs with such duals. Surprisingly,
the spectral function does not exhibit a Fermi surface, despite the fact that
the system is at finite charge density. We show that it has a phonino pole and
at low frequencies there is a depletion of spectral weight with a power-law
scaling which is governed by a locally quantum critical point.Comment: 5 pages. Content the same, but significant change of presentation.
Version to be published in Phys. Rev. Let
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