452 research outputs found
A Torsion Correction to the RR 4-Form Fieldstrength
The shifted quantization condition of the M-theory 4-form G_4 is well-known.
The most naive generalization to type IIA string theory fails, an orientifold
counterexample was found by Hori in hep-th/9805141. In this note we use
D2-brane anomaly cancellation to find the corresponding shifted quantization
condition in IIA. Our analysis is consistent with the known O4-plane tensions
if we include a torsion correction to the usual construction of G_4 from C_3, B
and G_2. The resulting Bianchi identities enforce that RR fluxes lift to
K-theory classes.Comment: 10 Pages, 1 eps figur
Black hole thermalization rate from brane anti-brane model
We develop the quasi-particle picture for Schwarzchild and far from extremal
black holes. We show that the thermalization equations of the black hole is
recovered from the model of branes and anti-branes. This can also be viewed as
a field theory explanation of the relationship between area and entropy for
these black holes. As a by product the annihilation rate of branes and
anti-branes is computed.Comment: 11 pages, late
Interface modes of two-dimensional composite structures
The surface modes of a composite consisting of aligned metallic wires with
square cross sections are investigated, on the basis of photonic band structure
calculations. The effective long-wavelength dielectric response function is
computed, as a function of the filling fraction. The dependence of the optical
absorption on the shape of the wires and the polarization of light is
discussed, and the effect of sharp corners analyzed. The effect of the
interaction between the wires on the localization of surface plasmons is also
addressed.Comment: 12 pages, 4 figures, to appear in Surf. Sc
Stringy NJL and Gross-Neveu models at finite density and temperature
Nonlocal stringy versions of the Nambu-Jona-Lasinio and Gross-Neveu models
arise in a certain limit of holographic QCD. We analyze the phase structure at
finite density and temperature at strong coupling in terms of probe branes in
the gravity dual. Comparison with the phase structure of the local field theory
models shows qualitative agreement with some aspects, and disagreement with
others. Finally, we explain how to construct the Landau potentials for these
models by taking the probe branes off-shell.Comment: 32 pages, uses JHEP3.cls; v2, references added, version to be
submitted to JHE
ABJM with Flavors and FQHE
We add fundamental matters to the N=6 Chern-Simons theory (ABJM theory), and
show that D6-branes wrapped over AdS_4 x S^3/Z_2 in type IIA superstring theory
on AdS_4 x CP^3 give its dual description with N=3 supersymmetry. We confirm
this by the arguments based on R-symmetry, supersymmetry, and brane
configuration of ABJM theory. We also analyze the fluctuations of the D6-brane
and compute the conformal dimensions of dual operators. In the presence of
fractional branes, the ABJM theory can model the fractional quantum Hall effect
(FQHE), with RR-fields regarded as the external electric-magnetic field. We
show that an addition of the flavor D6-brane describes a class of fractional
quantum Hall plateau transition.Comment: 23 pages, Latex, no figures; (v2) references added, typos correcte
Aspects of Puff Field Theory
We describe some features of the recently constructed "Puff Field Theory,"
and present arguments in favor of it being a field theory decoupled from
gravity. We construct its supergravity dual and calculate the entropy of this
theory in the limit of large 't Hooft coupling. We also determine the leading
irrelevant operator that governs its deviation from N=4 super Yang-Mills
theory.Comment: 31 pages, 1 figur
K-Theory and S-Duality: Starting Over from Square 3
Recently Maldacena, Moore, and Seiberg (MMS) have proposed a physical
interpretation of the Atiyah-Hirzebruch spectral sequence, which roughly
computes the K-homology groups that classify D-branes. We note that in IIB
string theory, this approach can be generalized to include NS charged objects
and conjecture an S-duality covariant, nonlinear extension of the spectral
sequence. We then compute the contribution of the MMS double-instanton
configuration to the derivation d_5. We conclude with an M-theoretic
generalization reminiscent of 11-dimensional E_8 gauge theory.Comment: 27 pages, 3 figure
Hydroxy-PCBs, PBDEs, and HBCDDs in serum from an elderly population of Swedish fishermen's wives and associations with bone density
Lack of human exposure data is frequently reported as a critical gap in risk assessments of environmental pollutants, especially regarding "new" pollutants. The objectives of this study were to assess serum levels of the persistent 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), hydroxylated polychlorinated biphenyl metabolites (OH-PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecanes (HBCDDs) in a group of Swedish middle-aged and elderly women expected to be relatively highly exposed, and to evaluate the impact of potential determinants (e.g., fish intake, age) for the inter-individual variation, as well as to investigate the association between these pollutants and bone density. No associations were found between bone mineral density or biochemical markers of bone metabolism and the analyzed environmental pollutants. Relatively high levels of CB-153 (median 260 ng/g fat) and Sigma(3)-OH- PCBs (median 1.7 ng/mL serum), and low concentrations of Sigma 6PBDEs (median 3.6 ng/g fat) were determined. Total level of HBCDDs in serum was quantified by gas chromatography with mass spectrometric detection (median 0.5 ng/g fat). HBCDD diastereomeric and enantiomeric patterns were determined by liquid chromatography with mass spectrometric detection. The dominating stereoisomer was (-)alpha-HBCDD, but 1-3% of gamma-HBCDD was also detected in the serum samples
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
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
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