200 research outputs found
A Note on Effective Lagrangians in Matrix Theory
We study the relation between the effective Lagrangian in Matrix Theory and
eleven dimensional supergravity. In particular, we provide a relationship
between supergravity operators and the corresponding terms in the
post-Newtonian approximation of Matrix Theory.Comment: 7 pages, use harvmac. References adde
Topological Vector Symmetry of BRSTQFT and Construction of Maximal Supersymmetry
The scalar and vector topological Yang-Mills symmetries determine a closed
and consistent sector of Yang-Mills supersymmetry. We provide a geometrical
construction of these symmetries, based on a horizontality condition on
reducible manifolds. This yields globally well-defined scalar and vector
topological BRST operators. These operators generate a subalgebra of maximally
supersymmetric Yang-Mills theory, which is small enough to be closed off-shell
with a finite set of auxiliary fields and large enough to determine the
Yang-Mills supersymmetric theory. Poincar\'e supersymmetry is reached in the
limit of flat manifolds. The arbitrariness of the gauge functions in BRSTQFTs
is thus removed by the requirement of scalar and vector topological symmetry,
which also determines the complete supersymmetry transformations in a twisted
way. Provided additional Killing vectors exist on the manifold, an equivariant
extension of our geometrical framework is provided, and the resulting
"equivariant topological field theory" corresponds to the twist of super
Yang-Mills theory on Omega backgrounds.Comment: 50 page
Resolution of the Nested Hierarchy for Rational sl(n) Models
We construct Drinfel'd twists for the rational sl(n) XXX-model giving rise to
a completely symmetric representation of the monodromy matrix. We obtain a
polarization free representation of the pseudoparticle creation operators
figuring in the construction of the Bethe vectors within the framework of the
quantum inverse scattering method. This representation enables us to resolve
the hierarchy of the nested Bethe ansatz for the sl(n) invariant rational
Heisenberg model. Our results generalize the findings of Maillet and Sanchez de
Santos for sl(2) models.Comment: 25 pages, no figure
A note on instanton counting for N=2 gauge theories with classical gauge groups
We study the prepotential of N=2 gauge theories using the instanton counting
techniques introduced by Nekrasov. For the SO theories without matter we find a
closed expression for the full prepotential and its string theory gravitational
corrections. For the more subtle case of Sp theories without matter we discuss
general features and compute the prepotential up to instanton number three. We
also briefly discuss SU theories with matter in the symmetric and antisymmetric
representations. We check all our results against the predictions of the
corresponding Seiberg-Witten geometries.Comment: 24 pages, LaTeX. v2: refs added. v3: typos correcte
Survival After Lung Transplantation of Cystic Fibrosis Patients Infected with Burkholderia cepacia Complex
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71603/1/j.1600-6143.2008.02186.x.pd
Five-dimensional AGT Conjecture and the Deformed Virasoro Algebra
We study an analog of the AGT relation in five dimensions. We conjecture that
the instanton partition function of 5D N=1 pure SU(2) gauge theory coincides
with the inner product of the Gaiotto-like state in the deformed Virasoro
algebra. In four dimensional case, a relation between the Gaiotto construction
and the theory of Braverman and Etingof is also discussed.Comment: 12 pages, reference added, minor corrections (typos, notation
changes, etc
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
On the Chiral Ring of N=1 Supersymmetric Gauge Theories
We consider the chiral ring of the pure N=1 supersymmetric gauge theory with
SU(N) gauge group and show that the classical relation S^{N^2}=0 is modified to
the exact quantum relation (S^N-\Lambda^{3N})^N=0.Comment: 5 pages. Comments and references adde
N=2 SYM Action as a BRST Exact Term, Topological Yang Mills and Instantons
By constructing a nilpotent extended BRST operator \bs that involves the
N=2 global supersymmetry transformations of one chirality, we show that the
standard N=2 off-shell Super Yang Mills Action can be represented as an exact
BRST term \bs \Psi, if the gauge fermion is allowed to depend on the
inverse powers of supersymmetry ghosts. By using this nonanalytical structure
of the gauge fermion (via inverse powers of supersymmetry ghosts), we give
field redefinitions in terms of composite fields of supersymmetry ghosts and
N=2 fields and we show that Witten's topological Yang Mills theory can be
obtained from the ordinary Euclidean N=2 Super Yang Mills theory directly by
using such field redefinitions. In other words, TYM theory is obtained as a
change of variables (without twisting). As a consequence it is found that
physical and topological interpretations of N=2 SYM are intertwined together
due to the requirement of analyticity of global SUSY ghosts. Moreover, when
after an instanton inspired truncation of the model is used, we show that the
given field redefinitions yield the Baulieu-Singer formulation of Topological
Yang Mills.Comment: Latex, 1+15 pages. Published versio
D-brane Instantons on the T^6/Z_3 orientifold
We give a detailed microscopic derivation of gauge and stringy instanton
generated superpotentials for gauge theories living on D3-branes at
Z_3-orientifold singularities. Gauge instantons are generated by D(-1)-branes
and lead to Affleck, Dine and Seiberg (ADS) like superpotentials in the
effective N=1 gauge theories with three generations of bifundamental and
anti/symmetric matter. Stringy instanton effects are generated by Euclidean
ED3-branes wrapping four-cycles on T^6/\Z_3. They give rise to Majorana masses
in one case and non-renormalizable superpotentials for the other cases. Finally
we determine the conditions under which ADS like superpotentials are generated
in N=1 gauge theories with adjoints, fundamentals, symmetric and antisymmetric
chiral matter.Comment: 31 pages, no figure
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