20 research outputs found
Rotating strings and D2-branes in type IIA reduction of M-theory on G2 manifold and their semiclassical limits
We consider rotating strings and D2-branes on type IIA background, which
arises as dimensional reduction of M-theory on manifold of G2 holonomy, dual to
N=1 gauge theory in four dimensions. We obtain exact solutions and explicit
expressions for the conserved charges. By taking the semiclassical limit, we
show that the rotating strings can reproduce only one type of semiclassical
behavior, exhibited by rotating M2-branes on G2 manifolds. Our further
investigation leads to the conclusion that the rotating D2-branes reproduce two
types of the semiclassical energy-charge relations known for membranes in
eleven dimensions.Comment: LaTeX, 29 pages, no figures; V2:comments added; V3:no changes, to
appear in JHE
KK-Masses in Dipole Deformed Field Theories
We reconsider aspects of non-commutative dipole deformations of field
theories. Among our findings there are hints to new phases with spontaneous
breaking of translation invariance (stripe phases), similar to what happens in
Moyal-deformed field theories. Furthermore, using zeta-function regularization,
we calculate quantum corrections to KK-state masses. The corrections coming
from non-planar diagrams show interesting but non-universal behaviour.
Depending on the type of interaction the corrections can make the KK-states
very heavy but also very light or even tachyonic. Finally we point out that the
dipole deformation of QED is not renormalizable!Comment: 21 pages, 5 figures, uses axodraw.sty, JHEP3.cls; v2:revised version
with minor change
Semiclassical Strings, Dipole Deformations of N=1 SYM and Decoupling of KK Modes
In this paper we investigate the recently found -deformed
Maldacena-Nunez background by studying the behavior of different semiclassical
string configurations. This background is conjectured to be dual to dipole
deformations of SYM. We compare our results to those in the pure
Maldacena-Nunez background and show that the energies of our string
configurations are higher than in the undeformed background. Thinking in the
lines of (hep-th/0505100) we argue that this is an evidence for better
decoupling of the Kaluza-Klein modes from the pure SYM theory excitations.
Moreover we are able to find a limit of the background in which the string
energy is independent of , these strings are interpreted as
corresponding to pure gauge theory effects.Comment: 31 pages, references added, new solutions in Section 7 presented, an
appendix added, to appear in JHE
On the perturbative chiral ring for marginally deformed N=4 SYM theories
For \cal{N}=1 SU(N) SYM theories obtained as marginal deformations of the
\cal{N}=4 parent theory we study perturbatively some sectors of the chiral ring
in the weak coupling regime and for finite N. By exploiting the relation
between the definition of chiral ring and the effective superpotential we
develop a procedure which allows us to easily determine protected chiral
operators up to n loops once the superpotential has been computed up to (n-1)
order. In particular, for the Lunin-Maldacena beta-deformed theory we determine
the quantum structure of a large class of operators up to three loops. We
extend our procedure to more general Leigh-Strassler deformations whose chiral
ring is not fully understood yet and determine the weight-two and weight-three
sectors up to two loops. We use our results to infer general properties of the
chiral ring.Comment: LaTex, 40 pages, 4 figures, uses JHEP3; v2: minor correction
Holographic Description of Glueball and Baryon in Noncommutative Dipole Gauge Theory
We study the glueball spectrum in the supersymmetric and non-supersymmetric
4D non-commutative dipole gauge theory from the holographic description. We
adopt the semiclassical WKB approximation to solve the dilaton and
antisymmetric tensor field equations on the dual supergravity backgrounds to
find the analytic formula of the spectrum of and glueballs,
respectively. In the supersymmetric theory we see that the dipole length plays
the intrinsic scale which reflects the discrete spectrum therein. In the
non-supersymmetric theory, the temperature (or the radius of compactification)
in there will now play the intrinsic scale and we see that the dipole has an
effect to produce attractive force between the gluons within the glueball. We
also study the confining force between the quarks within the baryon via strings
that hang into the dipole deformed AdS geometry and see that the dipole could
also produce an attractive force between the quarks. In particular, we find
that the baryon has two phases in which a big baryon is dual to the static
string while a small baryon is described by a moving dual string .Comment: Latex 18 page
Integrable twists in AdS/CFT
A class of marginal deformations of four-dimensional N=4 super Yang-Mills
theory has been found to correspond to a set of smooth, multiparameter
deformations of the S^5 target subspace in the holographic dual on AdS_5 x S^5.
We present here an analogous set of deformations that act on global toroidal
isometries in the AdS_5 subspace. Remarkably, certain sectors of the string
theory remain classically integrable in this larger class of so-called
gamma-deformed AdS_5 x S^5 backgrounds. Relying on studies of deformed
su(2)_gamma models, we formulate a local sl(2)_gamma Lax representation that
admits a classical, thermodynamic Bethe equation (based on the Riemann-Hilbert
interpretation of Bethe's ansatz) encoding the spectrum in the deformed AdS_5
geometry. This result is extended to a set of discretized, asymptotic Bethe
equations for the twisted string theory. Near-pp-wave energy spectra within
sl(2)_gamma and su(2)_gamma sectors provide a useful and stringent test of such
equations, demonstrating the reliability of this technology in a wider class of
string backgrounds. In addition, we study a twisted Hubbard model that yields
certain predictions of the dual beta-deformed gauge theory.Comment: v2: references and clarifications added, 46 page
Thermal Giant Graviton with Non-commutative Dipole Field
Using the type II near-extremal 3D-branes solution we apply the T-duality and
smeared twist to construct the supergravity backgrounds which dual to the 4D
finite temperature non-commutative dipole field theories. We first consider the
zero-temperature system in which, depending on the property of dipole vectors
it may be N=2, N=1 or N=0 theory. We investigate the rotating D3-brane
configurations moving on the spactimes and show that, for the cases of N=2 and
N =1 the rotating D3-brane could be blowed up to the stable spherical
configuration which is called as giant graviton and has a less energy than the
point-like graviton. The giant graviton configuration is stable only if its
angular momentum was less than a critical value of which is an increasing
function of the dipole strength. For the case of non-supersymmetric theory,
however, the spherical configuration has a larger energy than the point-like
graviton. We also find that the dipole field always render the dual giant
graviton to be more stable than the point-like graviton. The relation of dual
giant graviton energy with its angular momentum, which in the AdS/CFT
correspondence being the operator anomalous dimension is obtained. We
furthermore show that the temperature does not change the property of the giant
graviton, while it will render the dual giant graviton to be unstable.Comment: Latex 20 pages, add comments about BPS bound below (3.8
Spiky strings and giant magnons on S5
Recently, classical solutions for strings moving in AdS5 x S5 have played an
important role in understanding the AdS/CFT correspondence. A large set of them
were shown to follow from an ansatz that reduces the solution of the string
equations of motion to the study of a well-known integrable 1-d system known as
the Neumann-Rosochatius (NR) system. However, other simple solutions such as
spiky strings or giant magnons in S5 were not included in the NR ansatz. We
show that, when considered in the conformal gauge, these solutions can be also
accomodated by a version of the NR-system. This allows us to describe in detail
a giant magnon solution with two additional angular momenta and show that it
can be interpreted as a superposition of two magnons moving with the same
speed. In addition, we consider the spin chain side and describe the
corresponding state as that of two bound states in the infinite SU(3) spin
chain. We construct the Bethe ansatz wave function for such bound state.Comment: 33 pages, LaTeX, 2 figures. v2: minor corrections, v3: minor
corrections, figures enlarge
D1-brane in beta-Deformed Background
We study various configurations of rotating and wound D1-brane in AdS_5\times
S^5 background and in its beta deformed version. We find giant magnon and spike
solutions on the world-volume of D1-brane in AdS_5\times S^5 background. We
also analyse the equations of motion of D1-brane in beta-deformed background.
We show that in the limit of large electric flux on world-volume of D1-brane
they reduce to the equations that describe collection of large number of
fundamental strings. We also construct rotating and wound D1-brane solution
that has two equal spins on S^5_\gamma.Comment: 26 pages, appendices and a reference added, to appear in JHE
gamma_i Deformed Lax Pair for Rotating Strings in the Fast Motion Limit
A 3-parameter generalization of the Lunin-Maldacena background has recently
been constructed by Frolov. This gamma_i-deformed background is
non-supersymmetric. We consider strings in this gamma_i-deformed R \times S^5
background rotating in three orthogonal planes (the 3-spin sector) in a fast
motion limit, in which the total angular momentum J is assumed to be large. We
show that there exists a consistent transformation which takes the undeformed
equations of motion into the gamma_i-deformed equations of motion. This
transformation is used to construct a Lax pair for the bosonic part of the
gamma_i-deformed theory in the fast motion limit. This implies the
integrability of the bosonic part of the gamma_i-deformed string sigma model in
the fast motion limit.Comment: 21 page