227,152 research outputs found
Quantum phase transition in a Dp-Dq system
Using the top-down approach, we study intersecting Dp-Dq brane configuration
in string theory and find examples, where there can be a quantum phase
transition at zero temperature induced by the violation of the
Breitenlohner-Freedman (BF) bound at IR, which is done essentially by a
combination of charge density and magnetic fields. In particular, there exists
a Berezinskii-Kosterlitz-Thouless (BKT) type of transition for D3-D5 and D5-D5
systems. The study of the BKT type of transition is initiated by Jensen et al.
[Phys. Rev. Lett. {\bf 105}, 041601 (2010) ] for a D3-D5 system with nonzero
charge density and a magnetic field. Here, we show that one can have the BKT
transition for a D3-D5 system even in the absence of charge density but
requires multiple magnetic fields. In this case the field theory lives in 2+1
dimensions, whereas for the D5-D5 type, the transition requires the presence of
both the charge density and magnetic fields and the dual field theory lives on
a 3+1 dimensional spacetime. We also study the D3-D7 system but it does not
show the BKT type of transition.Comment: 1+37 pages; v2 Chern-Simon term for D3-D5 case presented, typos fixed
and a reference added; v3 Minor corrections, Chern-Simon term for D2-D4,
D4-D6, and D5-D7 added, also an appendix and few references added; v4 Journal
versio
Supersymmetric Giant Graviton Solutions in AdS_3
We parameterize all classical probe brane configurations that preserve 4
supersymmetries in (a) the extremal D1-D5 geometry, (b) the extremal D1-D5-P
geometry, (c) the smooth D1-D5 solutions proposed by Lunin and Mathur and (d)
global . These configurations consist of D1
branes, D5 branes and bound states of D5 and D1 branes with the property that a
particular Killing vector is tangent to the brane worldvolume at each point. We
show that the supersymmetric sector of the D5 brane worldvolume theory may be
analyzed in an effective 1+1 dimensional framework that places it on the same
footing as D1 branes. In global AdS and the corresponding Lunin-Mathur
solution, the solutions we describe are `bound' to the center of AdS for
generic parameters and cannot escape to infinity. We show that these probes
only exist on the submanifold of moduli space where the background
field and theta angle vanish. We quantize these probes in the near horizon
region of the extremal D1-D5 geometry and obtain the theory of long strings
discussed by Seiberg and Witten.Comment: 63 page
-brane type I superstring background fields in terms of type IIB ones by canonical method and T-duality approach
We consider type IIB superstring theory with embedded -brane and choose
boundary conditions which preserve half of the initial supersymmetry. In the
canonical approach that we use, boundary conditions are treated as canonical
constraints. The effective theory, obtained from the initial one on the
solution of boundary conditions, has the form of the type I superstring theory
with embedded -brane. We obtain the expressions for -brane background
fields of type I theory in terms of the -brane background fields of type
IIB theory. We show that beside known even fields, they contain
squares of odd ones, where is world-sheet parity
transformation, . We relate result of this paper and
the results of [1] using T-dualities along four directions orthogonal to
-brane
Mesons and Higgs branch in defect theories
We consider the defect theory obtained by intersecting D3- and D5-branes
along two common spatial directions. We work in the approximation in which the
D5-brane is a probe in the AdS_5xS^5 background. By adding worldvolume flux to
the D5-brane and choosing an appropriate embedding of the probe in AdS_5xS^5,
one gets a supersymmetric configuration in which some of the D3-branes
recombine with the D5-brane. We check this fact by showing that the D5-brane
can be regarded as a system of polarized D3-branes. On the field theory side
this corresponds to the Higgs branch of the defect theory, where some of the
fundamental hypermultiplet fields living on the intersection acquire a vacuum
expectation value. We study the spectrum of mesonic bound states of the defect
theory in this Higgs branch and show that it is continuous and gapless.Comment: 15 pages, LaTe
D1 and D5-Brane Actions in AdS_m x S^n
The kappa-invariant and supersymmetric actions of D1 and D5-branes in AdS_3 x
S^3 are investigated, as well as the action of a D5-brane in an AdS_5 x S^5
background. The action of a D5-brane lying totally in an AdS_3 x S^3 background
is found. Some progress was made towards finding the action for the D5-brane
free to move in the whole AdS_3 x S^3 x T^4 space, however the supersymmetric
action found here is not kappa-invariant and the reasons the method used did
not find a kappa-invariant solution are discussed.Comment: 17pp, Latex, improved explanations, a definition adde
The `s-rule' exclusion principle and vacuum interpolation in worldvolume dynamics
We show how the worldvolume realization of the Hanany-Witten effect for a
supersymmetric D5-brane in a D3 background also provides a classical
realization of the `s-rule' exclusion principle. Despite the supersymmetry, the
force on the D5-brane vanishes only in the D5 `ground state', which is shown to
interpolate between 6-dimensional Minkowski space and an -invariant
geometry. The M-theory analogue of these results is briefly
discussed.Comment: 25 pages, 9 figures, LaTeX JHEP styl
Supersymmetric probes on the conifold
We study the supersymmetric embeddings of different D-brane probes in the
AdS_5 x T^{1,1} geometry. The main tool employed is kappa symmetry and the
cases studied include D3-, D5- and D7-branes. We find a family of three-cycles
of the T^{1,1} space over which a D3-brane can be wrapped supersymmetrically
and we determine the field content of the corresponding gauge theory duals.
Supersymmetric configurations of D5-branes wrapping a two-cycle and of
spacetime filling D7-branes are also found. The configurations in which the
entire T^{1,1} space is wrapped by a D5-brane (baryon vertex) and a D7-brane
are also studied. Some other embeddings which break supersymmetry but are
nevertheless stable are also determined.Comment: 44 pages, LaTeX; v2: typos corrected, references added, discussion of
D5-brane embeddings improve
Superstring Theory on pp Waves with ADE Geometries
We study the BMN correspondence between certain Penrose limits of type IIB
superstrings on pp-wave orbifolds with geometries, and the set of
four-dimensional superconformal field theories constructed as
quiver gauge models classified by finite Lie algebras and affine
Kac-Moody algebras. These models have 16 preserved supercharges and
are based on systems of D3-branes and wrapped D5- and D7-branes. We derive
explicitly the metrics of these pp-wave orbifolds and show that the BMN
extension requires, in addition to D5-D5 open strings in bi-fundamental
representations, D5-D7 open strings involving orientifolds with gauge
symmetry. We also give the correspondence rule between leading string states
and gauge-invariant operators in the quiver gauge models.Comment: 62 page
- …