460 research outputs found
M-theory curves from warped AdS in Type IIB
We establish a close relation between recently constructed AdS solutions
in Type IIB supergravity, which describe the near-horizon limit of
5-brane junctions, and the curves wrapped by M5-branes in the M-theory
realization of the 5-brane junctions. This provides a geometric interpretation
of various objects appearing in the construction of the Type IIB solutions and
a physical interpretation of the regularity conditions. Conversely, the Type
IIB solutions provide explicit solutions to the equations defining the M-theory
curves associated with 5-brane junctions.Comment: 24 page
Supersymmetric D3/D5 for massive defects on curved space
We construct the holographic dual for SYM on and
coupled to massive supersymmetric quenched flavor
fields on a codimension-1 defect, which is and ,
respectively. The holographic description is in terms of a D3/probe D5 brane
system. We set up and reduce the BPS equations for D5-brane embeddings with
arbitrary supersymmetric deformations and partly solve them at the non-linear
level. The remaining equations are solved explicitly in a small-mass expansion.
We compute the contribution of the defect fields to the partition function on
S and compare to a field theory computation using supersymmetric
localization, for which we set up the matrix model. Both computations agree,
lending strong support to holographic probe brane constructions using D3/D5
configurations in general.Comment: 34 pages, 1 figur
Beyond the unitarity bound in AdS/CFT_(A)dS
In this work we expand on the holographic description of CFTs on de Sitter
(dS) and anti-de Sitter (AdS) spacetimes and examine how violations of the
unitarity bound in the boundary theory are recovered in the bulk physics. To
this end we consider a Klein-Gordon field on AdS_(d+1) conformally compactified
such that the boundary is (A)dS_d, and choose masses and boundary conditions
such that the corresponding boundary operator violates the CFT unitarity bound.
The setup in which the boundary is AdS_d exhibits a particularly interesting
structure, since in this case the boundary itself has a boundary. The bulk
theory turns out to crucially depend on the choice of boundary conditions on
the boundary of the AdS_d slices. Our main result is that violations to the
unitarity bound in CFTs on dS_d and AdS_d are reflected in the bulk through the
presence of ghost excitations. In addition, analyzing the setup with AdS_d on
the boundary allows us to draw conclusions on multi-layered AdS/CFT-type
dualities.Comment: 30 pages, 2 figures; reference adde
On minimal Type IIB solutions with commuting 7-branes
We construct Type IIB supergravity solutions with geometry
warped over a disc with two boundary points where 5-branes emerge and punctures
with 7-brane monodromy. They describe 5-brane junctions with two groups
of like-charged external 5-branes that are unconstrained by the -rule and an
additional group of constrained 5-branes. The dual 5d SCFTs include various
theories discussed previously in the literature. We match SCFT operators with
scaling dimension of with their representation in supergravity
to support the proposed dualities.Comment: 22 pages, 7 figure
Field Theory on Curved Noncommutative Spacetimes
We study classical scalar field theories on noncommutative curved spacetimes.
Following the approach of Wess et al. [Classical Quantum Gravity 22 (2005),
3511 and Classical Quantum Gravity 23 (2006), 1883], we describe noncommutative
spacetimes by using (Abelian) Drinfel'd twists and the associated *-products
and *-differential geometry. In particular, we allow for position dependent
noncommutativity and do not restrict ourselves to the Moyal-Weyl deformation.
We construct action functionals for real scalar fields on noncommutative curved
spacetimes, and derive the corresponding deformed wave equations. We provide
explicit examples of deformed Klein-Gordon operators for noncommutative
Minkowski, de Sitter, Schwarzschild and Randall-Sundrum spacetimes, which solve
the noncommutative Einstein equations. We study the construction of deformed
Green's functions and provide a diagrammatic approach for their perturbative
calculation. The leading noncommutative corrections to the Green's functions
for our examples are derived.Comment: SIGMA Special Issue on Noncommutative Spaces and Field
Spin 2 operators in holographic 4d SCFTs
A broad class of holographic duals for 4d SCFTs is based on
the general half-BPS solutions to M-theory constructed by Lin, Lunin
and Maldacena, and their Kaluza-Klein reductions to Type IIA. We derive the
equations governing spin 2 fluctuations around these solutions. The resulting
partial differential equations admit families of universal solutions which are
constructed entirely out of the generic data characterizing the background.
This implies the existence of families of spin 2 operators in the dual SCFTs,
in short superconformal multiplets which we identify.Comment: 16 page
Warped in Type IIB supergravity III: Global solutions with seven-branes
We extend our previous construction of global solutions to Type IIB
supergravity that are invariant under the superalgebra and are realized
on a spacetime of the form warped over a Riemann surface
by allowing the supergravity fields to have non-trivial monodromy at isolated punctures on . We obtain explicit solutions
for the case where is a disc, and the monodromy generators are
parabolic elements of physically corresponding to the
monodromy allowed in Type IIB string theory. On the boundary of the
solutions exhibit singularities at isolated points which correspond to
semi-infinite five-branes, as is familiar from the global solutions without
monodromy. In the interior of , the solutions are everywhere regular,
except at the punctures where monodromy resides and which
physically correspond to the locations of seven-branes. The solutions
have a compelling physical interpretation corresponding to fully localized
five-brane intersections with additional seven-branes, and provide candidate
holographic duals to the five-dimensional superconformal field theories
realized on such intersections.Comment: 43 pages, 6 figure
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