869 research outputs found
Holomorphic matrix models
This is a study of holomorphic matrix models, the matrix models which
underlie the conjecture of Dijkgraaf and Vafa. I first give a systematic
description of the holomorphic one-matrix model. After discussing its
convergence sectors, I show that certain puzzles related to its perturbative
expansion admit a simple resolution in the holomorphic set-up. Constructing a
`complex' microcanonical ensemble, I check that the basic requirements of the
conjecture (in particular, the special geometry relations involving chemical
potentials) hold in the absence of the hermicity constraint. I also show that
planar solutions of the holomorphic model probe the entire moduli space of the
associated algebraic curve. Finally, I give a brief discussion of holomorphic
models, focusing on the example of the quiver, for which I extract
explicitly the relevant Riemann surface. In this case, use of the holomorphic
model is crucial, since the Hermitian approach and its attending regularization
would lead to a singular algebraic curve, thus contradicting the requirements
of the conjecture. In particular, I show how an appropriate regularization of
the holomorphic model produces the desired smooth Riemann surface in the
limit when the regulator is removed, and that this limit can be described as a
statistical ensemble of `reduced' holomorphic models.Comment: 45 pages, reference adde
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
On the Matter of the Dijkgraaf--Vafa Conjecture
With the aim of extending the gauge theory -- matrix model connection to more
general matter representations, we prove that for various two-index tensors of
the classical gauge groups, the perturbative contributions to the glueball
superpotential reduce to matrix integrals. Contributing diagrams consist of
certain combinations of spheres, disks, and projective planes, which we
evaluate to four and five loop order. In the case of with antisymmetric
matter, independent results are obtained by computing the nonperturbative
superpotential for and 8. Comparison with the Dijkgraaf-Vafa approach
reveals agreement up to loops in matrix model perturbation theory, with
disagreement setting in at loops, being the dual Coxeter number.
At this order, the glueball superfield begins to obey nontrivial relations
due to its underlying structure as a product of fermionic superfields. We
therefore find a relatively simple example of an gauge theory
admitting a large expansion, whose dynamically generated superpotential
differs from the one obtained in the matrix model approach.Comment: 20 pages, harvmac. v2: added comments and reference
Mean-field Approach to the Derivation of Baryon Superpotential from Matrix Model
We discuss how to obtain the superpotential of the baryons and mesons for
SU(N) gauge theories with N flavour matter fields from matrix integral. We
apply the mean-field approximation for the matrix integral. Assuming the planar
limit of the self-consistency equation, we show that the result almost agrees
with the field theoretical result.Comment: rev2. ref. and related comments included, typos correcte
Gravitational F-terms of N=1 Supersymmetric Gauge Theories
We consider four-dimensional N=1 supersymmetric gauge theories in a
supergravity background. We use generalized Konishi anomaly equations and
R-symmetry anomaly to compute the exact perturbative and non-perturbative
gravitational F-terms. We study two types of theories: The first model breaks
supersymmetry dynamically, and the second is based on a gauge group. The
results are compared with the corresponding vector models. We discuss the
diagrammatic expansion of the theory.Comment: LaTeX2e, 23 pages, 2 figures. Added a reference and converted into
JHEP styl
Branched Matrix Models and the Scales of Supersymmetric Gauge Theories
In the framework of the matrix model/gauge theory correspondence, we consider
supersymmetric U(N) gauge theory with symmetry breaking pattern. Due
to the presence of the Veneziano--Yankielowicz effective superpotential, in
order to satisfy the --term condition , we are forced to
introduce additional terms in the free energy of the corresponding matrix model
with respect to the usual formulation. This leads to a matrix model formulation
with a cubic potential which is free of parameters and displays a branched
structure. In this way we naturally solve the usual problem of the
identification between dimensionful and dimensionless quantities. Furthermore,
we need not introduce the scale by hand in the matrix model. These facts
are related to remarkable coincidences which arise at the critical point and
lead to a branched bare coupling constant. The latter plays the role of the
and scale tuning parameter. We then show that a suitable
rescaling leads to the correct identification of the variables. Finally,
by means of the the mentioned coincidences, we provide a direct expression for
the prepotential, including the gravitational corrections, in terms of
the free energy. This suggests that the matrix model provides a triangulation
of the istanton moduli space.Comment: 1+18 pages, harvmac. Added discussion on the CSW relative shifts of
theta vacua and the odd phases at the critical point. References added and
typos correcte
Perturbative Computation of Glueball Superpotentials for SO(N) and USp(N)
We use the superspace method of hep-th/0211017 to prove the matrix model
conjecture for N=1 USp(N) and SO(N) gauge theories in four dimensions. We
derive the prescription to relate the matrix model to the field theory
computations. We perform an explicit calculation of glueball superpotentials.
The result is consistent with field theory expectations.Comment: 24 pages, 10 figure
Constructing Gauge Theory Geometries from Matrix Models
We use the matrix model -- gauge theory correspondence of Dijkgraaf and Vafa
in order to construct the geometry encoding the exact gaugino condensate
superpotential for the N=1 U(N) gauge theory with adjoint and symmetric or
anti-symmetric matter, broken by a tree level superpotential to a product
subgroup involving U(N_i) and SO(N_i) or Sp(N_i/2) factors. The relevant
geometry is encoded by a non-hyperelliptic Riemann surface, which we extract
from the exact loop equations. We also show that O(1/N) corrections can be
extracted from a logarithmic deformation of this surface. The loop equations
contain explicitly subleading terms of order 1/N, which encode information of
string theory on an orientifolded local quiver geometry.Comment: 52 page
Complex Curve of the Two Matrix Model and its Tau-function
We study the hermitean and normal two matrix models in planar approximation
for an arbitrary number of eigenvalue supports. Its planar graph interpretation
is given. The study reveals a general structure of the underlying analytic
complex curve, different from the hyperelliptic curve of the one matrix model.
The matrix model quantities are expressed through the periods of meromorphic
generating differential on this curve and the partition function of the
multiple support solution, as a function of filling numbers and coefficients of
the matrix potential, is shown to be the quasiclassical tau-function. The
relation to softly broken N=1 supersymmetric Yang-Mills theories is discussed.
A general class of solvable multimatrix models with tree-like interactions is
considered.Comment: 36 pages, 10 figures, TeX; final version appeared in special issue of
J.Phys. A on Random Matrix Theor
Properties of Chiral Wilson Loops
We study a class of Wilson Loops in N =4, D=4 Yang-Mills theory belonging to
the chiral ring of a N=2, d=1 subalgebra. We show that the expectation value of
these loops is independent of their shape. Using properties of the chiral ring,
we also show that the expectation value is identically 1. We find the same
result for chiral loops in maximally supersymmetric Yang-Mills theory in three,
five and six dimensions. In seven dimensions, a generalized Konishi anomaly
gives an equation for chiral loops which closely resembles the loop equations
of the three dimensional Chern-Simons theory.Comment: 15 pages, two pictures, some references adde
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