1,203 research outputs found
On the quantization of isomonodromic deformations on the torus
The quantization of isomonodromic deformation of a meromorphic connection on
the torus is shown to lead directly to the Knizhnik-Zamolodchikov-Bernard
equations in the same way as the problem on the sphere leads to the system of
Knizhnik-Zamolodchikov equations. The Poisson bracket required for a
Hamiltonian formulation of isomonodromic deformations is naturally induced by
the Poisson structure of Chern-Simons theory in a holomorphic gauge fixing.
This turns out to be the origin of the appearance of twisted quantities on the
torus.Comment: 13 pages, LaTex2
Neukodifikation des lnternationalen Privatrechts in Argentinien
Am 1. August 2015 ist in Argentinien ein neues „Zivil- und Handelsgesetzbuch“ in Kraft getreten, das auch das Internationale Privatrecht umfasst. Während in Argentinien lange der Plan verfolgt wurde, das Internationale Privatrecht in einem eigenen Gesetz zu regeln, setzte sich schließlich die Auffassung durch, diese Materie im Rahmen des neuen Zivilgesetzbuchs zu behandeln. Daraus ergeben sich substantielle Beschränkungen; so wurden in das Gesetz keine Vorschriften über die Anerkennung ausländischer Entscheidungen aufgenommen. Anderseits enthält das Gesetz nicht nur Vorschriften über das anwendbare Recht, sondern auch über die internationale Zuständigkeit. Ein eigener Abschnitt umfasst dazu die allgemeinen Grundsätze, während die einzelnen Gerichtsstände für die jeweiligen Materien zusammen mit dem anwendbaren Recht geregelt werden. Das Gesetz zielt darauf ab, die bisher im Zivilgesetzbuch verstreuten kollisionsrechtlichen Vorschriften und die dazu ergangene Rechtsprechung systematisch zu ordnen und zu modernisieren. Dabei wurden auch ausländische Gesetze und die internationalen Verträge auf diesem Gebiet umfassend berücksichtigt.A new “Civil and Commercial Code” containing a codification of private international law is in force in Argentina from 1 August 2015. The ambitious efforts, which persisted for a long time in Argentina, to create a distinct law for private international law have been replaced by the more practical attempt to regulate this area of law within the new Civil Code. This has substantial implications, as for instance the enforcement of foreign judgments is not regulated in the new codification. On the other hand, it contains not only provisions on the applicable law, but also on international jurisdiction. This topic is regulated in a general way in a separate chapter, but also in detail combined with the articles on the applicable law as concerns the individual fora. While the old Civil Code had only scattered provisions on conflict of laws, the new regulation is aimed at systematizing and modernizing this area of law within a cohesive text, considering the doctrine and jurisprudence in Argentina together with comparative law and international conventions
Six-Dimensional (1,0) Superconformal Models and Higher Gauge Theory
We analyze the gauge structure of a recently proposed superconformal field
theory in six dimensions. We find that this structure amounts to a weak
Courant-Dorfman algebra, which, in turn, can be interpreted as a strong
homotopy Lie algebra. This suggests that the superconformal field theory is
closely related to higher gauge theory, describing the parallel transport of
extended objects. Indeed we find that, under certain restrictions, the field
content and gauge transformations reduce to those of higher gauge theory. We
also present a number of interesting examples of admissible gauge structures
such as the structure Lie 2-algebra of an abelian gerbe, differential crossed
modules, the 3-algebras of M2-brane models and string Lie 2-algebras.Comment: 31+1 pages, presentation slightly improved, version published in JM
Yang-Mills-Chern-Simons Supergravity
N=(1,0) supergravity in six dimensions admits AdS_3\times S^3 as a vacuum
solution. We extend our recent results presented in hep-th/0212323, by
obtaining the complete N=4 Yang-Mills-Chern-Simons supergravity in D=3, up to
quartic fermion terms, by S^3 group manifold reduction of the six dimensional
theory. The SU(2) gauge fields have Yang-Mills kinetic terms as well as
topological Chern-Simons mass terms. There is in addition a triplet of matter
vectors. After diagonalisation, these fields describe two triplets of
topologically-massive vector fields of opposite helicities. The model also
contains six scalars, described by a GL(3,R)/SO(3) sigma model. It provides the
first example of a three-dimensional gauged supergravity that can obtained by a
consistent reduction of string-theory or M-theory and that admits AdS_3 as a
vacuum solution. There are unusual features in the reduction from
six-dimensional supergravity, owing to the self-duality condition on the 3-form
field. The structure of the full equations of motion in N=(1,0) supergravity in
D=6 is also elucidated, and the role of the self-dual field strength as torsion
is exhibited.Comment: Latex, 22 pages, hep-th number correcte
AdS Duals of Matrix Strings
We review recent work on the holographic duals of type II and heterotic
matrix string theories described by warped AdS_3 supergravities. In particular,
we compute the spectra of Kaluza-Klein primaries for type I, II supergravities
on warped AdS_3xS^7 and match them with the primary operators in the dual
two-dimensional gauge theories. The presence of non-trivial warp factors and
dilaton profiles requires a modification of the familiar dictionary between
masses and ``scaling'' dimensions of fields and operators. We present these
modifications for the general case of domain wall/QFT correspondences between
supergravities on warped AdS_{d+1}xS^q geometries and super Yang-Mills theories
with 16 supercharges.Comment: 7 pages, Proceedings of the RTN workshop ``The quantum structure of
spacetime and the geometric nature of fundamental interactions'', Leuven,
September 200
The general gaugings of maximal d=9 supergravity
We use the embedding tensor method to construct the most general maximal
gauged/massive supergravity in d=9 dimensions and to determine its extended
field content. Only the 8 independent deformation parameters (embedding tensor
components, mass parameters etc.) identified by Bergshoeff \textit{et al.} (an
SL(2,R) triplet, two doublets and a singlet can be consistently introduced in
the theory, but their simultaneous use is subject to a number of quadratic
constraints. These constraints have to be kept and enforced because they cannot
be used to solve some deformation parameters in terms of the rest. The
deformation parameters are associated to the possible 8-forms of the theory,
and the constraints are associated to the 9-forms, all of them transforming in
the conjugate representations. We also give the field strengths and the gauge
and supersymmetry transformations for the electric fields in the most general
case. We compare these results with the predictions of the E11 approach,
finding that the latter predicts one additional doublet of 9-forms, analogously
to what happens in N=2, d=4,5,6 theories.Comment: Latex file, 43 pages, reference adde
Gauged N=4 supergravities
We present the gauged N=4 (half-maximal) supergravities in four and five
spacetime dimensions coupled to an arbitrary number of vector multiplets. The
gaugings are parameterized by a set of appropriately constrained constant
tensors, which transform covariantly under the global symmetry groups SL(2) x
SO(6,n) and SO(1,1) x SO(5,n), respectively. In terms of these tensors the
universal Lagrangian and the Killing Spinor equations are given. The known
gaugings, in particular those originating from flux compactifications, are
incorporated in the formulation, but also new classes of gaugings are found.
Finally, we present the embedding chain of the five dimensional into the four
dimensional into the three dimensional gaugings, thereby showing how the
deformation parameters organize under the respectively larger duality groups.Comment: 36 pages, v2: references added, comments added, v3: published
version, references added, typos corrected, v4: sign mistakes in footnote 4
and equation (2.13) correcte
Electrodynamics with Lorentz-violating operators of arbitrary dimension
The behavior of photons in the presence of Lorentz and CPT violation is
studied. Allowing for operators of arbitrary mass dimension, we classify all
gauge-invariant Lorentz- and CPT-violating terms in the quadratic Lagrange
density associated with the effective photon propagator. The covariant
dispersion relation is obtained, and conditions for birefringence are
discussed. We provide a complete characterization of the coefficients for
Lorentz violation for all mass dimensions via a decomposition using
spin-weighted spherical harmonics. The resulting nine independent sets of
spherical coefficients control birefringence, dispersion, and anisotropy. We
discuss the restriction of the general theory to various special models,
including among others the minimal Standard-Model Extension, the isotropic
limit, the case of vacuum propagation, the nonbirefringent limit, and the
vacuum-orthogonal model. The transformation of the spherical coefficients for
Lorentz violation between the laboratory frame and the standard Sun-centered
frame is provided. We apply the results to various astrophysical observations
and laboratory experiments. Astrophysical searches of relevance include studies
of birefringence and of dispersion. We use polarimetric and dispersive data
from gamma-ray bursts to set constraints on coefficients for Lorentz violation
involving operators of dimensions four through nine, and we describe the mixing
of polarizations induced by Lorentz and CPT violation in the cosmic-microwave
background. Laboratory searches of interest include cavity experiments. We
present the theory for searches with cavities, derive the experiment-dependent
factors for coefficients in the vacuum-orthogonal model, and predict the
corresponding frequency shift for a circular-cylindrical cavity.Comment: 58 pages two-column REVTeX, accepted in Physical Review
Vacua of N=10 three dimensional gauged supergravity
We study scalar potentials and the corresponding vacua of N=10 three
dimensional gauged supergravity. The theory contains 32 scalar fields
parametrizing the exceptional coset space . The admissible gauge groups considered in this work involve both
compact and non-compact gauge groups which are maximal subgroups of
and , respectively. These gauge groups are
given by for , , , and . We
find many AdS critical points with various unbroken gauge symmetries. The
relevant background isometries associated to the maximally supersymmetric
critical points at which all scalars vanish are also given. These correspond to
the superconformal symmetries of the dual conformal field theories in two
dimensions.Comment: 37 pages no figures, typos corrected and a little change in the
forma
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