328 research outputs found

### 5D Yang-Mills instantons from ABJM Monopoles

In the presence of a background supergravity flux, N M2-branes will expand
via the Myers effect into M5-branes wrapped on a fuzzy three-sphere. In
previous work the fluctuations of the M2-branes were shown to be described by
the five-dimensional Yang-Mills gauge theory associated to D4-branes. We show
that the ABJM prescription for eleven-dimensional momentum in terms of magnetic
flux lifts to an instanton flux of the effective five-dimensional Yang-Mills
theory on the sphere, giving an M-theory interpretation for these instantons.Comment: 29 pages, Latex; v2: added references and a comment on the
graviphoton coupling in section 5; v3: typos corrected and references adde

### BPS Geometries and AdS Bubbles

Recently, 1/2-BPS AdS bubble solutions have been obtained by Lin, Lunin and
Maldacena, which correspond to Fermi droplets in phase space in the dual CFT
picture. They can be thought of as generalisations of 1/2-BPS AdS black hole
solutions in five or seven dimensional gauged supergravity. In this paper, we
extend these solutions by invoking additional gauge fields and scalar fields in
the supergravity Lagrangians, thereby obtaining AdS bubble generalisations of
the previously-known multi-charge AdS black solutions of gauged supergravity.
We also obtain analogous AdS bubble solutions in four-dimensional gauged
supergravity. Our solutions generically preserve supersymmetry fractions 1/4,
1/8 and 1/8 in seven, five and four dimensions respectively. They can be lifted
to M-theory or type IIB string theory, using previously known formulae for the
consistent Pauli sphere reductions that yield the gauged supergravities. We
also find similar solutions in six-dimensional gauged supergravity, and discuss
their lift to the massive type IIA theory.Comment: Latex, 11 page

### Geometry of The Embedding of Supergravity Scalar Manifolds in D=11 and D=10

Several recent papers have made considerable progress in proving the
existence of remarkable consistent Kaluza-Klein sphere reductions of D=10 and
D=11 supergravities, to give gauged supergravities in lower dimensions. A proof
of the consistency of the full gauged SO(8) reduction on S^7 from D=11 was
given many years ago, but from a practical viewpoint a reduction to a smaller
subset of the fields can be more manageable, for the purposes of lifting
lower-dimensional solutions back to the higher dimension. The major complexity
of the spherical reduction Ansatze comes from the spin-0 fields, and of these,
it is the pseudoscalars that are the most difficult to handle. In this paper we
address this problem in two cases. One arises in a truncation of SO(8) gauged
supergravity in four dimensions to U(1)^4, where there are three pairs of
dilatons and axions in the scalar sector. The other example involves the
truncation of SO(6) gauged supergravity in D=5 to a subsector containing a
scalar and a pseudoscalar field, with a potential that admits a second
supersymmetric vacuum aside from the maximally-supersymmetric one. We briefly
discuss the use of these emdedding Ansatze for the lifting of solutions back to
the higher dimension.Comment: Latex, 24 pages, typos correcte

### Consistent SO(6) Reduction Of Type IIB Supergravity on S^5

Type IIB supergravity can be consistently truncated to the metric and the
self-dual 5-form. We obtain the complete non-linear Kaluza-Klein S^5 reduction
Ansatz for this theory, giving rise to gravity coupled to the fifteen
Yang-Mills gauge fields of SO(6) and the twenty scalars of the coset
SL(6,R)/SO(6). This provides a consistent embedding of this subsector of N=8,
D=5 gauged supergravity in type IIB in D=10. We demonstrate that the
self-duality of the 5-form plays a crucial role in the consistency of the
reduction. We also discuss certain necessary conditions for a theory of gravity
and an antisymmetric tensor in an arbitrary dimension D to admit a consistent
sphere reduction, keeping all the massless fields. We find that it is only
possible for D=11, with a 4-form field, and D=10, with a 5-form. Furthermore,
in D=11 the full bosonic structure of eleven-dimensional supergravity is
required, while in D=10 the 5-form must be self-dual. It is remarkable that
just from the consistency requirement alone one would discover D=11 and type
IIB supergravities, and that D=11 is an upper bound on the dimension.Comment: Latex, 14 pages, typos corrected and comments adde

### Towards a Realization of the Condensed-Matter/Gravity Correspondence in String Theory via Consistent Abelian Truncation

We present an embedding of the 3-dimensional relativistic Landau-Ginzburg
model for condensed matter systems in an $\mathcal{N}=6$, $U(N)\times U(N)$
Chern-Simons-matter theory (the ABJM model) by consistently truncating the
latter to an abelian effective field theory encoding the collective dynamics of
${\cal O}(N)$ of the ${\cal O}(N^2)$ modes. In fact, depending on the VEV on
one of the ABJM scalars, a mass deformation parameter $\mu$ and the
Chern-Simons level number $k$, our abelianization prescription allows us to
interpolate between the abelian Higgs model with its usual multi-vortex
solutions and a $\phi^4$ theory. We sketch a simple condensed matter model that
reproduces all the salient features of the abelianization. In this context, the
abelianization can be interpreted as giving a dimensional reduction from four
dimensions.Comment: 4 pages, revtex; reference added, typo corrected; added clarifying
paragraphs at end of introduction and on pages 3-4. Version accepted to PR

### Diffusion in an Expanding Plasma using AdS/CFT

We consider the diffusion of a non-relativistic heavy quark of fixed mass M,
in a one-dimensionally expanding and strongly coupled plasma using the AdS/CFT
duality. The Green's function constructed around a static string embedded in a
background with a moving horizon, is identified with the noise correlation
function in a Langevin approach. The (electric) noise decorrelation is of order
1/T(\tau) while the velocity de-correlation is of order MD(\tau)/T(\tau). For
MD>1, the diffusion regime is segregated and the energy loss is Langevin-like.
The time dependent diffusion constant D(\tau) asymptotes its adiabatic limit
2/\pi\sqrt{\lambda} T(\tau) when \tau/\tau_0=(1/3\eta_0\tau_0)^3 where \eta_0
is the drag coefficient at the initial proper time \tau_0.Comment: 19 pages, 2 figures, minor corrections, version to appear in JHE

### Correspondence principle for a brane in Minkowski space and vector mesons

We consider a 3-brane of positive cosmological constant (de Sitter) in
D-dimensional Minkowski space. We show that the Poincare algebra in the bulk
yields a SO(4,2) algebra when restricted to the brane. In the limit of zero
cosmological constant (flat brane), this algebra turns into the conformal
algebra on the brane. We derive a correspondence principle for Minkowski space
analogous to the AdS/CFT correspondence. We discuss explicitly the cases of
scalar and gravitational fields. For a 3-brane of finite thickness in the
transverse directions, we obtain a spectrum for vector gravitational
perturbations which correspond to vector mesons. The spectrum agrees with the
one obtained in truncated AdS space by de Teramond and Brodsky provided D=10
and the bulk mass scale M is of order the geometric mean of the Planck mass
($\bar M$) on the brane and $\Lambda_{QCD}$ ($M \sim (\bar M
\Lambda_{QCD})^{1/2} \sim 10^9$ GeV).Comment: 8 pages in two-column ReVTeX

### Non-extremal Charged Rotating Black Holes in Seven-Dimensional Gauged Supergravity

We obtain the solution for non-extremal charged rotating black holes in
seven-dimensional gauged supergravity, in the case where the three rotation
parameters are set equal. There are two independent charges, corresponding to
gauge fields in the U(1)xU(1) abelian subgroup of the SO(5) gauge group. A new
feature in these solutions, not seen previously in lower-dimensional examples,
is that the first-order "odd-dimensional self-duality" equation for the 4-form
field strength plays a non-trivial role. We also study the BPS limit of our
solutions where the black holes become supersymmetric. Our results are of
significance for the AdS_7/CFT_6 correspondence in M-theory.Comment: Latex, 12 pages, typos corrected and a reference adde

### Abelian-Higgs and Vortices from ABJM: towards a string realization of AdS/CMT

We present ans\"{a}tze that reduce the mass-deformed ABJM model to gauged
Abelian scalar theories, using the fuzzy sphere matrices $G^\alpha$. One such
reduction gives a Toda system, for which we find a new type of nonabelian
vortex. Another gives the standard Abelian-Higgs model, thereby allowing us to
embed all the usual (multi-)vortex solutions of the latter into the ABJM model.
By turning off the mass deformation at the level of the reduced model, we can
also continuously deform to the massive $\phi^4$ theory in the massless ABJM
case. In this way we can embed the Landau-Ginzburg model into the AdS/CFT
correspondence as a consistent truncation of ABJM. In this context, the mass
deformation parameter $\mu$ and a field VEV $$ act as $g$ and $g_c$
respectively, leading to a well-motivated AdS/CMT construction from string
theory. To further this particular point, we propose a simple model for the
condensed matter field theory that leads to an approximate description for the
ABJM abelianization. Finally, we also find some BPS solutions to the
mass-deformed ABJM model with a spacetime interpretation as an M2-brane ending
on a spherical M5-brane.Comment: 43 pages, latex, explanations added in the introduction, end of
section 4, and on page 2

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