1,349 research outputs found
The Coulomb branch of N=1 supersymmetric gauge theory with adjoint and fundamental matter
We consider N=1 SU(N_c) gauge theory with an adjoint matter field , N_f
flavors of fundamentals Q and antifundamentals \tQ, and tree-level
superpotential of the form \tQ\Phi^l Q. This superpotential is relevant or
marginal for . The theory has a Coulomb branch which is not
lifted by quantum corrections. We find the exact effective gauge coupling on
the Coulomb branch in terms of a family of hyperelliptic curves, thus providing
a generalization of known results about N=2 SUSY QCD to N=1 context. The
Coulomb branch has singular points at which mutually nonlocal dyons become
massless. These singularities presumably correspond to new N=1 superconformal
fixed points. We discuss them in some detail for N_c=2, N_f=1.Comment: 12 pages, revte
Branes and N=1 Duality in String Theory
We propose a construction of dual pairs in four dimensional N=1
supersymmetric Yang-Mills theory using branes in type IIA string theory.Comment: 8 pages, harvmac; minor changes, additional reference
Irreversibility of the Renormalization Group Flow in Two Dimensional Quantum Gravity
We argue that the torus partition sum in (super) gravity, which counts
physical states in the theory, is a decreasing function of the renormalization
group scale. As an application we chart the space of
models coupled to (super) gravity, confirming and extending ideas due to A.
Zamolodchikov, and discuss briefly string theory, where our results imply that
the number of degrees of freedom decreases with time.Comment: 14 pages, PUPT-133
Symmetries and Mass Splittings in QCD Coupled to Adjoint Fermions
Two dimensional QCD coupled to fermions in the adjoint representation of the
gauge group , a useful toy model of QCD strings, is supersymmetric for a
certain ratio of quark mass and gauge coupling constant. Here we study the
theory in the vicinity of the supersymmetric point; in particular we exhibit
the algebraic structure of the model and show that the mass splittings as one
moves away from the supersymmetric point obey a universal relation of the form
. We discuss the connection of
this relation to string and quark model expectations and verify it numerically
for large . At least for low lying states the corrections
are extremely small. We also discuss a natural generalization of QCD with
an infinite number of couplings, which preserves SUSY. This leads to a Landau
-- Ginzburg description of the theory, and may be useful for defining a scaling
limit in which smooth worldsheets appear.Comment: 16 pages + 3 figures available upon request, harvmac, EFI-93-6
N=1 RG Flows, Product Groups, and a-Maximization
We explore new IR phenomena and dualities, arising for product groups, in the
context of N=1 supersymmetric gauge theories. The RG running of the multiple
couplings can radically affect each other. For example, an otherwise IR
interacting coupling can be driven to be instead IR free by an arbitrarily
small, but non-zero, initial value of another coupling. Or an otherwise IR free
coupling can be driven to be instead IR interacting by an arbitrarily small
non-zero initial value of another coupling. We explore these and other
phenomena in N=1 examples, where exact results can be obtained using
a-maximization. We also explore the various possible dual gauge theories, e.g.
by dualizing one gauge group with the other treated as a weakly gauged flavor
symmetry, along with previously proposed duals for the theories deformed by
A_k-type Landau-Ginzburg superpotentials. We note that this latter duality, and
all similar duality examples, always have non-empty superconformal windows,
within which both the electric and dual A_k superpotentials are relevant.Comment: 36 pages, 8 figure
Scattering of Open and Closed Strings in 1+1 Dimensions
The ground ring structure of 1+1 dimensional string theory leads to an
infinite set of non linear recursion relations among the `bulk' scattering
amplitudes of open and closed tachyons on the disk, which fix them uniquely.
The relations are generated by the action of the ring on the tachyon modules;
associativity of this action determines all structure constants. This algebraic
structure may allow one to relate the continuum picture to a matrix model.Comment: 16 page
Lagrange Multipliers and Couplings in Supersymmetric Field Theory
In hep-th/0312098 it was argued that by extending the ``-maximization'' of
hep-th/0304128 away from fixed points of the renormalization group, one can
compute the anomalous dimensions of chiral superfields along the flow, and
obtain a better understanding of the irreversibility of RG flow in four
dimensional supersymmetric field theory. According to this proposal, the role
of the running couplings is played by certain Lagrange multipliers that are
introduced in the construction. We show that one can choose a parametrization
of the space of couplings in which the Lagrange multipliers can indeed be
identified with the couplings, and discuss the consequences of this for weakly
coupled gauge theory.Comment: 13 pages, harvma
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