4,301 research outputs found
Higher-derivative non-Abelian gauge fields via the Faddeev-Jackiw formalism
In this paper we analyze two higher-derivative theories, the generalized
electrodynamics and the Alekseev-Arbuzov-Baikov's effective Lagrangian from the
point of view of Faddeev-Jackiw sympletic approach. It is shown that the full
set of constraint is obtained directly from the zero-mode eigenvectors, and
that they are in accordance with known results from Dirac's theory, a remnant
and recurrent issue in the literature. The method shows to be rather economical
in relation to the Dirac's one, obviating thus unnecessary classification and
calculations. Afterwards, to conclude we construct the transition-amplitude of
the non-Abelian theory following a constrained BRST-method.Comment: 17 page
Nonperturbative Aspects of the two-dimensional Massive Gauged Thirring Model
In this paper we present a study based on the use of functional techniques on
the issue of insertions of massive fermionic fields in the two-dimensional
massless Gauged Thirring Model. As it will be shown, the fermionic mass
contributes to the Green's functions in a surprisingly simple way, leaving
therefore the original nonperturbative nature of the massless results still
intact in the massive theory. Also, by means of complementarity, we present a
second discussion of the massive model, now at its bosonic representation.Comment: 18 pages, to appear at Int. J. Mod. Phys.
Path-ordered Phase Factors in Scalar Quantum Electrodynamics
Starting from linear equations for the complex scalar field, the two- and
three-point Green's functions are obtained in the infrared approximation. We
show that the infrared singularity factorizes in the vertex function as in
spinorial QED, reproducing in a straightforward way the result of lenghty
perturbative calculations.Comment: 11 pages, LaTe
What's Wrong with Pauli-Villars Regularization in ?
In this letter we argue that there is no ambiguity between the Pauli-Villars
and other methods of regularization in (2+1)-dimensional quantum
electrodynamics with respect to dynamical mass generation, provided we properly
choose the couplings for the regulators.Comment: 07 pages, Latex, no figure
Equivalence of Many-Gluon Green Functions in Duffin-Kemmer-Petieu and Klein-Gordon-Fock Statistical Quantum Field Theories
We prove the equivalence of many-gluon Green functions in
Duffin-Kemmer-Petieu and Klein-Gordon-Fock statistical quantum field theories.
The proof is based on the functional integral formulation for the statistical
generating functional in a finite-temperature quantum field theory. As an
illustration, we calculate one-loop polarization operators in both theories and
show that their expressions indeed coincide.Comment: 8 page
Variational Formulation for Quaternionic Quantum Mechanics
A quaternionic version of Quantum Mechanics is constructed using the
Schwinger's formulation based on measurements and a Variational Principle.
Commutation relations and evolution equations are provided, and the results are
compared with other formulations.Comment: Talk given at ICCA*, May 26-30 of 2008, Campinas, SP, Brazil. 18
pages, no figur
Causal Propagators for Algebraic Gauges
Applying the principle of analytic extension for generalized functions we
derive causal propagators for algebraic non-covariant gauges. The so generated
manifestly causal gluon propagator in the light-cone gauge is used to evaluate
two one-loop Feynman integrals which appear in the computation of the
three-gluon vertex correction. The result is in agreement with that obtained
through the usual prescriptions.Comment: LaTex, 09 pages, no figure
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