1,624 research outputs found
The String Theory Approach to Generalized 2D Yang-Mills Theory
We calculate the partition function of the ( and ) generalized
theory defined on an arbitrary Riemann surface. The result which is
expressed as a sum over irreducible representations generalizes the Rusakov
formula for ordinary YM_2 theory. A diagrammatic expansion of the formula
enables us to derive a Gross-Taylor like stringy description of the model. A
sum of 2D string maps is shown to reproduce the gauge theory results. Maps with
branch points of degree higher than one, as well as ``microscopic surfaces''
play an important role in the sum. We discuss the underlying string theory.Comment: TAUP-2182-94, 53 pages of LaTeX and 5 uuencoded eps figure
Higher Algebraic Structures and Quantization
We derive (quasi-)quantum groups in 2+1 dimensional topological field theory
directly from the classical action and the path integral. Detailed computations
are carried out for the Chern-Simons theory with finite gauge group. The
principles behind our computations are presumably more general. We extend the
classical action in a d+1 dimensional topological theory to manifolds of
dimension less than d+1. We then ``construct'' a generalized path integral
which in d+1 dimensions reduces to the standard one and in d dimensions
reproduces the quantum Hilbert space. In a 2+1 dimensional topological theory
the path integral over the circle is the category of representations of a
quasi-quantum group. In this paper we only consider finite theories, in which
the generalized path integral reduces to a finite sum. New ideas are needed to
extend beyond the finite theories treated here.Comment: 62 pages + 16 figures (revised version). In this revision we make
some small corrections and clarification
Free Energies and Probe Actions for Near-horizon D-branes and D1 + D5 System
By working with the free energy for the type II supergravity near-horizon
solution of N coincident non-extremal Dp-branes we study the transitions among
the non-conformal Dp-brane system, the perturbative super Yang-Mills theory and
a certain system associated with M theory. We derive a relation between this
free energy and the action of a Dp-brane probe in the N Dp-brane background.
Constructing the free energy for the five dimensional black hole labeled by the
D1-brane and D5-brane charges we find the similar relation between it and the
action of a D1 or D5 brane probe in the D1 + D5 brane background. These
relations are explained by the massive open strings stretched between the
relevant D-branesComment: 14 pages, LaTeX2e, no figure
Interacting Strings in Matrix String Theory
It is here explained how the Green-Schwarz superstring theory arises from
Matrix String Theory. This is obtained as the strong YM-coupling limit of the
theory expanded around its BPS instantonic configurations, via the
identification of the interacting string diagram with the spectral curve of the
relevant configuration. Both the GS action and the perturbative weight
, where is the Euler characteristic of the world-sheet
surface and the string coupling, are obtained.Comment: 11 pages, no figures, two references adde
N=1* model superpotential revisited (IR behaviour of N=4 limit)
The one-loop contribution to the superpotential, in particular the
Veneziano-Yankielowicz potential in N=1 supersymmetric Yang-Mills model is
discussed from an elementary field theory method and the matrix model point of
view. Both approaches are based on the Renormalization Group variation of the
superconformal N=4 supersymmetric Yang-Mills model.Comment: 31 page
Super Yang-Mills With Flavors From Large N_f Matrix Models
We consider the exact effective superpotential of N=1 U(N_c) super Yang-Mills
theory with N_f massive flavors an additional adjoint Higgs field. We use the
proposal of Dijkgraaf and Vafa to calculate the superpotential in terms of a
matrix model with a large number of flavors. We do this by gauging the flavor
symmetry and forcing this sector in a classical vacuum. This gives rise to a
2-matrix model of ADE type A_2, and large flavors. This approach allows us to
add an arbitrary polynomial tree level superpotential for the Higgs field, and
use strict large N methods in the matrix model.Comment: 17 p. LaTeX, 17 p. v2: ref added, typos corrected. v3: typos
corrected. v4: typos corrected, extended discussion on classical solution
Exact Superpotentials from Matrix Models
Dijkgraaf and Vafa (DV) have conjectured that the exact superpotential for a
large class of N=1 SUSY gauge theories can be extracted from the planar limit
of a certain holomorphic matrix integral. We test their proposal against
existing knowledge for a family of deformations of N=4 SUSY Yang-Mills theory
involving an arbitrary polynomial superpotential for one of the three adjoint
chiral superfields. Specifically, we compare the DV prediction for these models
with earlier results based on the connection between SUSY gauge theories and
integrable systems. We find complete agreement between the two approaches. In
particular we show how the DV proposal allows the extraction of the exact
eigenvalues of the adjoint scalar in the confining vacuum and hence computes
all related condensates of the finite-N gauge theory. We extend these results
to include Leigh-Strassler deformations of the N=4 theory.Comment: 28 pages, 1 figure, latex with JHEP.cls, replaced with typos
corrected and one clarifying commen
New insight into WDVV equation
We show that Witten-Dijkgraaf-Verlinde-Verlinde equation underlies the
construction of N=4 superconformal multi--particle mechanics in one dimension,
including a N=4 superconformal Calogero model.Comment: 16 pages, no figures, LaTeX file, PACS: 04.60.Ds; 11.30.P
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
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