26,757 research outputs found
Reducible systems and embedding procedures in the canonical formalism
We propose a systematic method of dealing with the canonical constrained
structure of reducible systems in the Dirac and symplectic approaches which
involves an enlargement of phase and configuration spaces, respectively. It is
not necessary, as in the Dirac approach, to isolate the independent subset of
constraints or to introduce, as in the symplectic analysis, a series of
lagrange multipliers-for-lagrange multipiers. This analysis illuminates the
close connection between the Dirac and symplectic approaches of treating
reducible theories, which is otherwise lacking. The example of p-form gauge
fields (p=2,3) is analyzed in details.Comment: Latex 23 pages, some corrections and improvements in the text. To
appear in Annals of Physic
BV QUANTIZATION OF A VECTOR-TENSOR GAUGE THEORY WITH TOPOLOGICAL COUPLING
We use the BV quantization method for a theory with coupled tensor and vector
gauge fields through a topological term. We consider in details the
reducibility of the tensorial sector as well as the appearance of a mass term
in the effective vectorial theory .Comment: 10 pages, Late
Axial and gauge anomalies in a theory with one and two-form gauge fields
We study the problem of axial and gauge anomalies in a reducible theory
involving vector and tensor gauge fields coupled in a topological way. We
consider that vector and axial fermionic currents couple with the tensor field
in the same topological manner as the vector gauge one. This kind of coupling
leads to an anomalous axial current, contrarily to the results found in
literature involving other tensor couplings, where no anomaly is obtained.Comment: 9 pages, Latex - To appear in Phys. Lett.
Compactification of gauge theories and the gauge invariance of massive modes
We study the gauge invariance of the massive modes in the compactification of
gauge theories from D=5 to D=4. We deal with Abelian gauge theories of rank one
and two, and with non-Abelian ones of rank one. We show that St\"uckelberg
fields naturally appear in the compactification mechanism, contrarily to what
usually occurs in literature where they are introduced by hand, as a trick, to
render gauge invariance for massive theories. We also show that in the
non-Abelian case they appear in a very different way when compared with their
usual implementation in the non-Abelian Proca model.Comment: 5 pages, Revtex (multicol), minor correction
Functional versus canonical quantization of a nonlocal massive vector-gauge theory
It has been shown in literature that a possible mechanism of mass generation
for gauge fields is through a topological coupling of vector and tensor fields.
After integrating over the tensor degrees of freedom, one arrives at an
effective massive theory that, although gauge invariant, is nonlocal. Here we
quantize this nonlocal resulting theory both by path integral and canonical
procedures. This system can be considered as equivalent to one with an infinite
number of time derivatives and consequently an infinite number of momenta. This
means that the use of the canonical formalism deserves some care. We show the
consistency of the formalism we use in the canonical procedure by showing that
the obtained propagators are the same as those of the (Lagrangian) path
integral approach. The problem of nonlocality appears in the obtainment of the
spectrum of the theory. This fact becomes very transparent when we list the
infinite number of commutators involving the fields and their velocities.Comment: 12 pages, Latex, to appear in J. Math. Phy
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