175 research outputs found
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
Renormalizability of a quark-gluon model with soft BRST breaking in the infrared region
We prove the renormalizability of a quark-gluon model with a soft breaking of
the BRST symmetry, which accounts for the modification of the large distance
behavior of the quark and gluon correlation functions. The proof is valid to
all orders of perturbation theory, by making use of softly broken Ward
identities.Comment: 20 pages, no figures. Preprint number added in v2
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
Ghost Condensates and Dynamical Breaking of SL(2,R) in Yang-Mills in the Maximal Abelian Gauge
Ghost condensates of dimension two in SU(N) Yang-Mills theory quantized in
the Maximal Abelian Gauge are discussed. These condensates turn out to be
related to the dynamical breaking of the SL(2,R) symmetry present in this gaugeComment: 16 pages, LaTeX2e, final version to appear in J. Phys.
On the Renormalizability of Noncommutative U(1) Gauge Theory - an Algebraic Approach
We investigate the quantum effects of the nonlocal gauge invariant operator
in the
noncommutative U(1) action and its consequences to the infrared sector of the
theory. Nonlocal operators of such kind were proposed to solve the infrared
problem of the noncommutative gauge theories evading the questions on the
explicit breaking of the Lorentz invariance. More recently, a first step in the
localization of this operator was accomplished by means of the introduction of
an extra tensorial matter field, and the first loop analysis was carried out
. We will complete this localization
avoiding the introduction of new degrees of freedom beyond those of the
original action by using only BRST doublets. This will allow us to make a
complete BRST algebraic study of the renormalizability of the theory, following
Zwanziger's method of localization of nonlocal operators in QFT.Comment: standard Latex no figures, version2 accepted in J. Phys A: Math Theo
Perturbative Beta Function of N=2 Super Yang-Mills Theories
An algebraic proof of the nonrenormalization theorem for the perturbative
beta function of the coupling constant of N=2 Super Yang-Mills theory is
provided. The proof relies on a fundamental relationship between the N=2
Yang-Mills action and the local gauge invariant polynomial Tr phi^2, phi(x)
being the scalar field of the N=2 vector gauge multiplet. The
nonrenormalization theorem for the beta function follows from the vanishing of
the anomalous dimension of Tr phi^2.Comment: 20 pages, Latex2e, name of institutions correcte
Caracterização de dois fungos causadores de mildio pulverulento em Senna e Desmodium no Brasil.
Resumo 1755. Edição dos resumos do 44º Congresso Brasileiro de Fitopatologia, 2011, Bento Gonçalves
An Algebraic Criterion for the Ultraviolet Finiteness of Quantum Field Theories
An algebraic criterion for the vanishing of the beta function for
renormalizable quantum field theories is presented. Use is made of the descent
equations following from the Wess-Zumino consistency condition. In some cases,
these equations relate the fully quantized action to a local gauge invariant
polynomial. The vanishing of the anomalous dimension of this polynomial enables
us to establish a nonrenormalization theorem for the beta function ,
stating that if the one-loop order contribution vanishes, then will
vanish to all orders of perturbation theory. As a by-product, the special case
in which is only of one-loop order, without further corrections, is
also covered. The examples of the N=2,4 supersymmetric Yang-Mills theories are
worked out in detail.Comment: 1+32 pages, LaTeX2e, typos correcte
Topological and Universal Aspects of Bosonized Interacting Fermionic Systems in (2+1)d
General results on the structure of the bosonization of fermionic systems in
d are obtained. In particular, the universal character of the bosonized
topological current is established and applied to generic fermionic current
interactions. The final form of the bosonized action is shown to be given by
the sum of two terms. The first one corresponds to the bosonization of the free
fermionic action and turns out to be cast in the form of a pure Chern-Simons
term, up to a suitable nonlinear field redefinition. We show that the second
term, following from the bosonization of the interactions, can be obtained by
simply replacing the fermionic current by the corresponding bosonized
expression.Comment: 29 pages, RevTe
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