Navegação Ciências Exatas e da Terra por Autor "Girotti, Horacio Oscar"
Resultados 1-20 de 39
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Anyons and singular gauge transformations
(1989) [Artigo de periódico]A (2 + 1 )-dimensional theory of charged scalar particles coupled to an abehan gauge field with Chern-Slmons term In the action is canonically quantlzed in the Coulomb and superaxlal gauges The gauge transformatmn linking ... -
Attractive forces between electrons in (2+1) - dimensional QED
(1992) [Artigo de periódico]Vacuum polarization effects are nonperturbatively incorporated into the photon propagator to eliminate the severe infrared problems characteristic of (2+1)-dimensional QED (QED₃). The theory is thus rephrased in terms of ... -
Born series and unitarity in noncommutative quantum mechanics
(2008) [Artigo de periódico]This paper is dedicated to present model independent results for noncommutative quantum mechanics. We determine sufficient conditions for the convergence of the Born series and, in the sequel, unitarity is proved in full ... -
Canonical derivation of the gluon propagator in the temporal gauge
(1986) [Artigo de periódico]We reexamine the problem of obtaining, within the operator approach, an unambiguous expression for the longitudinal gluon propagator in the temporal gauge. A regularization procedure respecting Gauss's law and the Hermiticity ... -
Canonical quantization of a two-dimensional model with anomalous breaking of gauge invariance
(1986) [Artigo de periódico]We investigate in detail the operator quantum dynamics of a two-dimensional model exhibiting anomalous breaking of gauge invariance. The equal-time algebra is systematically obtained by using the Dirac-bracket formalism ... -
Chiral bosonization
(1988) [Artigo de periódico]We show that the Dirac-bracket quantization of a single self-dual field leads naturally to the bosonization formulas. We find a numerical parameter describing the soliton charge and unveiling hidden soliton sectors. -
Chiral bosons and improper constraints
(1994) [Artigo de periódico]We argue that a consistent quantization of the Floreanini-Jackiw model, as a constrained system, should start by recognizing the improper nature of the constraints. Then, each boundary condition defines a problem which ... -
Chiral bosons through linear constraints
(1992) [Artigo de periódico]We study in detail the quantization of a model which apparently describes chiral bosons. The model is based on the idea that the chiral condition could be implemented through a linear constraint. We show that the space of ... -
Comment on "self dual fields as charge-density solitons"
(1988) [Artigo de periódico] -
A consistent noncommutative field theory : the Wess-Zumino model
(2000) [Artigo de periódico]We show that the noncommutative Wess–Zumino model is renormalizable to all orders of perturbation theory. The noncommutative scalar potential by itself is non-renormalizable but the Yukawa terms demanded by supersymmetry ... -
Coupling of fermions to the three-dimensional noncommutative CP/sup N-1/ model : minimal and supersymmetric extensions
(2004) [Artigo de periódico]We consider the coupling of fermions to the three-dimensional noncommutative CPN21 model. In the case of minimal coupling, although the infrared behavior of the gauge sector is improved, there are dangerous ~quadratic! ... -
Duality symmetry in the schwarz-sen model
(1997) [Artigo de periódico]The continuous extension of the discrete duality symmetry of the Schwarz-Sen model is studied. The corresponding infinitesimal generator Q turns out to be local, gauge invariant, and metric independent. Furthermore, Q ... -
Dynamics of gauge systems and Dirac's conjecture
(1985) [Artigo de periódico]For systems possessing only first-class constraints, we rigorously prove that the secondary constraints act as independent generators of gauge transformations (Dirac's conjecture). The proof essentially consists in ... -
Fractional statistics in the chern-simons theory
(1990) [Artigo de periódico]A (2 + 1)-dimensional theory of charged scalar particles coupled to an abelian gauge field with a Chern-Simons term in the action is canonically quantized in a generalized linear non-covariant gauge. We find, in all gauges, ... -
Hamiltonian formulation of QED in the superaxial gauge
(1982) [Artigo de periódico]We present a hamlltonian formulation of QED in a fully fixed axial gauge. The equal-time commutators for all field variables are computed and are shown to lead to the correct equations of motion. The constraints and gauge ... -
Lorentz symmetry breaking in the noncommutative Wess-Zumino model : one loop corrections
(2006) [Artigo de periódico]In this paper we deal with the issue of Lorentz symmetry breaking in quantum field theories formulated in a noncommutative space-time. We show that, unlike in some recent analysis of quantum gravity effects, supersymmetry ... -
Low energy limit of the chern-simons theory coupled to fermions
(1997) [Artigo de periódico]We study the nonrelativistic limit of the theory of a quantum Chern-Simons field minimally coupled to Dirac fermions. To get the nonrelativistic effective Lagrangian one has to incorporate vacuum polarization and anomalous ... -
Manifestly covariant approach for the one-soliton sector
(1978) [Artigo de periódico]The one-loop contributions to the meson propagator and to the meson-soliton scattering amplitude in the one-soliton sector are analyzed using ordinary Feynman rules. It is found that, at the level of the propagator, the ... -
Noncommutative quantum mechanics as a gauge theory
(2009) [Artigo de periódico]The classical counterpart of noncommutative quantum mechanics is a constrained system containing only second-class constraints. The embedding procedure formulated by Batalin, Fradkin and Tyutin (BFT) enables one to transform ... -
Noncommutative quantum mechanics : uniqueness of the functional description
(2008) [Artigo de periódico]The generalized Weyl transform of index is used to implement the time-slice definition of the phase space path integral yielding the Feynman kernel in the case of noncommutative quantum mechanics. As expected, this ...
