2,862 research outputs found
Interacting spin 0 fields with torsion via Duffin-Kemmer-Petiau theory
Here we study the behaviour of spin 0 sector of the DKP field in spaces with
torsion. First we show that in a Riemann-Cartan manifold the DKP field presents
an interaction with torsion when minimal coupling is performed, contrary to the
behaviour of the KG field, a result that breaks the usual equivalence between
the DKP and the KG fields.
Next we analyse the case of Teleparallel Equivalent of General Relativity
Weitzenbock manifold, showing that in this case there is a perfect agreement
between KG and DKP fields. The origins of both results are also discussed.Comment: 10 pages, no figures, uses REVTEX. Changes in the presentation, minor
misprints and one equation corrected. References updated. To appear in
General Relativity and Gravitatio
Gauged Thirring Model in the Heisenberg Picture
We consider the (2+1)-dimensional gauged Thirring model in the Heisenberg
picture. In this context we evaluate the vacuum polarization tensor as well as
the corrected gauge boson propagator and address the issues of generation of
mass and dynamics for the gauge boson (in the limits of QED and Thirring
model as a gauge theory, respectively) due to the radiative corrections.Comment: 14 pages, LaTex, no figure
Conformal invariance of massless Duffin-Kemmer-Petiau theory in Riemannian space-times
We investigate the conformal invariance of massless Duffin-Kemmer-Petiau
theory coupled to riemannian space-times. We show that, as usual, in the
minimal coupling procedure only the spin 1 sector of the theory -which
corresponds to the electromagnetic field- is conformally invariant. We show
also that the conformal invariance of the spin 0 sector can be naturally
achieved by introducing a compensating term in the lagrangian. Such a procedure
-besides not modifying the spin 1 sector- leads to the well-known conformal
coupling between the scalar curvature and the massless Klein-Gordon-Fock field.
Going beyond the riemannian spacetimes, we briefly discuss the effects of a
nonvanishing torsion in the scalar case.Comment: 8 pages, no figures. Major changes in contend and results. To appear
in Class.Quant.Gra
Spin 1 fields in Riemann-Cartan space-times "via" Duffin-Kemmer-Petiau theory
We consider massive spin 1 fields, in Riemann-Cartan space-times, described
by Duffin-Kemmer-Petiau theory. We show that this approach induces a coupling
between the spin 1 field and the space-time torsion which breaks the usual
equivalence with the Proca theory, but that such equivalence is preserved in
the context of the Teleparallel Equivalent of General Relativity.Comment: 8 pages, no figures, revtex. Dedicated to Professor Gerhard Wilhelm
Bund on the occasion of his 70th birthday. To appear in Gen. Rel. Grav.
Equations numbering corrected. References update
Some aspects of the synchronization in coupled maps
Through numerical simulations we analyze the synchronization time and the
Lyapunov dimension of a coupled map lattice consisting of a chain of chaotic
logistic maps exhibiting power law interactions. From the observed behaviors we
find a lower bound for the size of the lattice, independent of the range
and strength of the interaction, which imposes a practical lower bound in
numerical simulations for the system to be considered in the thermodynamic
limit. We also observe the existence of a strong correlation between the
averaged synchronization time and the Lyapunov dimension. This is an
interesting result because it allows an analytical estimation of the
synchronization time, which otherwise requires numerical simulations.Comment: 4 pages, 6 figure
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