610 research outputs found
N=2 S-duality via Outer-automorphism Twists
Compactification of 6d N=(2,0) theory of type G on a punctured Riemann
surface has been effectively used to understand S-dualities of 4d N=2 theories.
We can further introduce branch cuts on the Riemann surface across which the
worldvolume fields are transformed by the discrete symmetries associated to
those of the Dynkin diagram of type G. This allows us to generate more
S-dualities, and in particular to reproduce a couple of S-dual pairs found
previously by Argyres and Wittig.Comment: 8 pages, 6 figure
The Coulomb branch of N=1 supersymmetric SU(N_c) x SU(N_c) gauge theories
We analyze the low energy behavior of N=1 supersymmetric gauge theories with
SU(N_c) x SU(N_c) gauge group and a Landau-Ginzburg type superpotential. These
theories contain fundamentals transforming under one of the gauge groups as
well as bifundamental matter which transforms as a fundamentals under each. We
obtain the parametrization of the gauge coupling on the Coulomb branch in terms
of a hyperelliptic curve. The derivation of this curve involves making use of
Seiberg's duality for SQCD as well as the classical constraints for N_f=N_c+1
and the quantum modified constraints for N_f=N_c.Comment: 16 pages, no figures, revtex; typos correcte
Renormalization Group and Dynamics of Supersymmetric Gauge Theories
We discuss questions related to renormalization group and to nonperturbative
aspects of non-Abelian gauge theories with N=2 and/or N=1 supersymmetry.
Results on perturbative and nonperturbative functions of these theories
are reviewed, and new mechanisms of confinement and dynamical symmetry breaking
recently found in a class of , and theories are
discussed.Comment: 13 pages, 3 figures, uses ws-p9-75x6-50.cls. Lecture given at the
Second Conference on the ERG, Rome 200
Sp(N) higher-derivative F-terms via singular superpotentials
We generalize the higher-derivative F-terms introduced by Beasley and Witten
(hep-th/0409149) for SU(2) superQCD to Sp(N) gauge theories with fundamental
matter. We generate these terms by integrating out massive modes at tree level
from an effective superpotential on the chiral ring of the microscopic theory.
Though this superpotential is singular, its singularities are mild enough to
permit the unambiguous identification of its minima, and gives sensible answers
upon integrating out massive modes near any given minimum.Comment: 15 pages, 6 figure
Generalized Konishi anomaly, Seiberg duality and singular effective superpotentials
Using the generalized Konishi anomaly (GKA) equations, we derive the
effective superpotential of four-dimensional N=1 supersymmetric SU(n) gauge
theory with n+2 fundamental flavors. We find, however, that the GKA equations
are only integrable in the Seiberg dual description of the theory, but not in
the direct description of the theory. The failure of integrability in the
direct, strongly coupled, description suggests the existence of
non-perturbative corrections to the GKA equations.Comment: 20 pages; v3: corrected the comparison to the SU(2) cas
Tree scattering amplitudes of the spin-4/3 fractional superstring I: the untwisted sectors
Scattering amplitudes of the spin-4/3 fractional superstring are shown to
satisfy spurious state decoupling and cyclic symmetry (duality) at tree-level
in the string perturbation expansion. This fractional superstring is
characterized by the spin-4/3 fractional superconformal algebra---a
parafermionic algebra studied by Zamolodchikov and Fateev involving chiral
spin-4/3 currents on the world-sheet in addition to the stress-energy tensor.
Examples of tree scattering amplitudes are calculated in an explicit c=5
representation of this fractional superconformal algebra realized in terms of
free bosons on the string world-sheet. The target space of this model is
three-dimensional flat Minkowski space-time with a level-2 Kac-Moody so(2,1)
internal symmetry, and has bosons and fermions in its spectrum. Its closed
string version contains a graviton in its spectrum. Tree-level unitarity (i.e.,
the no-ghost theorem for space-time bosonic physical states) can be shown for
this model. Since the critical central charge of the spin-4/3 fractional
superstring theory is 10, this c=5 representation cannot be consistent at the
string loop level. The existence of a critical fractional superstring
containing a four-dimensional space-time remains an open question.Comment: 42 pages, 4 figures, latex, IASSNS-HEP-93/57, CLNS-92/117
On the Moduli Space of N = 2 Supersymmetric G_2 Gauge Theory
We apply the method of confining phase superpotentials to N = 2
supersymmetric Yang-Mills theory with the exceptional gauge group G_2. Our
findings are consistent with the spectral curve of the periodic Toda lattice,
but do not agree with the hyperelliptic curve suggested previously in the
literature. We also apply the method to theories with fundamental matter,
treating both the example of SO(5) and G_2.Comment: 14 pages, LaTeX, 1 figure, reference adde
Kac and New Determinants for Fractional Superconformal Algebras
We derive the Kac and new determinant formulae for an arbitrary (integer)
level fractional superconformal algebra using the BRST cohomology
techniques developed in conformal field theory. In particular, we reproduce the
Kac determinants for the Virasoro () and superconformal () algebras.
For there always exist modules where the Kac determinant factorizes
into a product of more fundamental new determinants. Using our results for
general , we sketch the non-unitarity proof for the minimal series;
as expected, the only unitary models are those already known from the coset
construction. We apply the Kac determinant formulae for the spin-4/3
parafermion current algebra ({\em i.e.}, the fractional superconformal
algebra) to the recently constructed three-dimensional flat Minkowski
space-time representation of the spin-4/3 fractional superstring. We prove the
no-ghost theorem for the space-time bosonic sector of this theory; that is, its
physical spectrum is free of negative-norm states.Comment: 33 pages, Revtex 3.0, Cornell preprint CLNS 93/124
On singular effective superpotentials in supersymmetric gauge theories
We study N=1 supersymmetric SU(2) gauge theory in four dimensions with a
large number of massless quarks. We argue that effective superpotentials as a
function of local gauge-invariant chiral fields should exist for these
theories. We show that although the superpotentials are singular, they
nevertheless correctly describe the moduli space of vacua, are consistent under
RG flow to fewer flavors upon turning on masses, and also reproduce by a
tree-level calculation the higher-derivative F-terms calculated by Beasely and
Witten (hep-th/0409149) using instanton methods. We note that this phenomenon
can also occur in supersymmetric gauge theories in various dimensions.Comment: 21 pages, 5 figures; minor errors correcte
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