Publications (3)0 Total impact
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ABSTRACT: Semi-local quantum critical behaviour in $D-1$ spacetime dimensions can be
holographically described by metrics that are conformal to
$AdS_2\times\mathbb{R}^{D-2}$, with the conformal factor characterised by a
parameter $\eta$. We analyse such "$\eta$-geometries" in a top-down setting by
focussing on the $U(1)^4$ truncation of D=4 N=8 gauged supergravity. The model
has extremal black hole solutions carrying three non-zero electric or magnetic
charges which approach $AdS_4$ in the UV and an $\eta=1$ geometry in the IR.
Adding a fourth charge provides a mechanism to resolve the singularity of the
$\eta$-geometry, replacing it with an $AdS_2\times\mathbb{R}^2$ factor in the
IR, while maintaining a large region where the $\eta$-geometry scaling is
approximately valid. Some of the magnetically charged black hole solutions
preserve supersymmetry while others just preserve it in the IR. Finally, we
show that $\eta$-geometries, with various values of $\eta$, can be obtained
from the dimensional reduction of geometries consisting of $AdS$ or Lifshitz
geometries with flat directions.
12/2012;
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ABSTRACT: The stability properties of a family of magnetic $AdS_{3}\times
\mathbb{R}^{2}$ solutions of D=5, SO(6) gauged SUGRA are investigated in more
detail. We construct an analogous family of magnetic $AdS_{2}\times
\mathbb{R}^{2}$ solutions of D=4, SO(8) gauged SUGRA, including a family of
supersymmetric solutions, and also investigate their stability. We construct
supersymmetric domain walls that interpolate between AdS_5 and an
$AdS_3\times\mathbb{R}^2$ solution and also between AdS_4 and an
$AdS_2\times\mathbb{R}^2$ solution which provide stable zero temperature ground
states for the corresponding dual CFTs. We also construct new families of
electric $AdS_{2}\times \mathbb{R}^{3}$ and $AdS_{2}\times \mathbb{R}^{2}$
solutions.
12/2011;
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ABSTRACT: We investigate spatially modulated instabilities of magnetically charged
$AdS_{2}\times\mathbb{R}^2$, $AdS_{3}\times\mathbb{R}^2$ and
$AdS_{2}\times\mathbb{R}^3$ backgrounds in a broad class of theories, including
those arising from KK reductions of ten and eleven dimensional supergravity. We
show that magnetically charged black brane solutions in D=4,5 spacetime
dimensions, whose zero temperature near horizon limit approach these
backgrounds, can have instabilities that are dual to phases with current
density waves that spontaneously break translation symmetry. Our examples
include spatially modulated instabilities for a new class of magnetic black
brane solutions of D=5 SO(6) gauged supergravity, that we construct in closed
form, which are dual to new phases of N=4 SYM theory.
09/2011;
