26 research outputs found
Superconformal current algebras and topological field theories
Topological conformal field theories based on superconformal current algebras
are constructed. The models thus obtained are the supersymmetric version of the
coset theories. Their topological conformal algebra is generated by
operators of dimensions , and and can be regarded as an extension of
the twisted superconformal algebra. These models possess an extended
supersymmetry whose generators are exact in the topological BRST cohomology.Comment: 16 pages, phyzzx, US-FT-11/9
Coset Constructions in Chern-Simons Gauge Theory
Coset constructions in the framework of Chern-Simons topological gauge
theories are studied. Two examples are considered: models of the types
with and
coprime integers, and . In the latter
case it is shown that the Chern-Simons wave functionals can be identified with
t he characters of the minimal unitary models, and an explicit representation
of the knot (Verlinde) operators acting on the space of characters is
obtained.Comment: 15 page
M-Theory Giant Gravitons with C field
We find giant graviton configurations of an M5-brane probe in the D=11
supergravity background generated by a stack of non-threshold (M2,M5) bound
states. The M5-brane probe shares three directions with the background and
wraps a two-sphere transverse to the bound states. For a particular value of
the worldvolume gauge field of the PST formalism, there exist solutions of the
equations of motion for which the M5-brane probe behaves as a wave propagating
in the (M2,M5) background. We have checked that the probe breaks the
supersymmetry of the background exactly as a massless particle moving along the
trajectory of its center of mass.Comment: 11 pages, LaTeX; v2: references adde
Topological current algebras in two dimensions
Two-dimensional topological field theories possessing a non-abelian current
symmetry are constructed. The topological conformal algebra of these models is
analysed. It differs from the one obtained by twisting the superconformal
models and contains generators of dimensions , and that close a
linear algebra. Our construction can be carried out with one and two bosonic
currents and the resulting theories can be interpreted as topological sigma
models for group manifoldsComment: 16 page
Singularity Resolution in Gauged Supergravity and Conifold Unification
We obtain a unified picture for the conifold singularity resolution. We
propose that gauged supergravity, through a novel prescription for the
twisting, provides an appropriate framework to smooth out singularities in the
context of gravity duals of supersymmetric gauge theories.Comment: 13 pages, harvmac, one figure; v2: reference adde
Gravity duals of 2d supersymmetric gauge theories
We find new supergravity solutions generated by D5-branes wrapping a
four-cycle and preserving four and two supersymmetries. We first consider the
configuration in which the fivebranes wrap a four-cycle in a Calabi-Yau
threefold, which preserves four supersymmetries and is a gravity dual to the
Coulomb branch of two-dimensional gauge theories with N=(2,2) supersymmetry. We
also study the case of fivebranes wrapping a co-associative four-cycle in a
manifold of G_2-holonomy, which provides a gravity dual of N=(1,1)
supersymmetric Yang-Mills theory in two dimensions. We also discuss the
addition of unquenched fundamental matter fields to these backgrounds and find
the corresponding gravity solutions with flavor brane sources.Comment: 34 pages + appendices; v2: minor improvement
On the free field realization of the osp(1|2) current algebra
The free field representation of the osp(1|2) current algebra is analyzed.
The four point conformal blocks of the theory are studied. The structure
constants for the product of an arbitrary primary operator and a primary field
that transforms according to the fundamental representation of osp(1|2) are
explicitly calculated.Comment: 11 pages, phyzz
Graded Parafermions
A graded generalization of the Z_k parafermionic current osp(1|2)/U(1) coset
conformal field theory. The structure of the parafermionic highest-weight
modules is analyzed and the dimensions of the fields of the theory are
determined. A free field realization of the graded parafermionic system is
obtained and the structure constants of the current algebra are found. Although
the theory is not unitary, it presents good reducibility properties.Comment: 27 pages, LaTeX, 1 eps file. Typos correcte
Topological supergravity structure of non-critical superstring theories
We obtain a bosonization prescription that allows to represent the
energy-momentum tensor and supersymmetry generators of non-critical superstring
theories with minimal matter as those of topological supergravity. Superstrings
with and world-sheet supersymmetry are considered. The topological
symmetry associated with the topological supergravity representation is
studied. It is shown, in particular, that the compatibility of this topological
structure with the supersymmetry enhances the superconformal symmetry of the
models concerned.Comment: 15 pages, phyzzx, no figure
Polynomials for Torus Links from Chern-Simons Gauge Theories
Invariant polynomials for torus links are obtained in the framework of the
Chern-Simons topological gauge theory. The polynomials are computed as vacuum
expectation values on the three-sphere of Wilson line operators representing
the Verlinde algebra of the corresponding rational conformal field theory. In
the case of the gauge theory our results provide explicit expressions
for the Jones polynomial as well as for the polynomials associated to the
-state () vertex models (Akutsu-Wadati polynomials). By means of the
Chern-Simons coset construction, the minimal unitary models are analyzed,
showing that the corresponding link invariants factorize into two
polynomials. A method to obtain skein rules from the Chern-Simons knot
operators is developed. This procedure yields the eigenvalues of the braiding
matrix of the corresponding conformal field theory.Comment: 50 page