15,775 research outputs found
The effect of different regulators in the non-local field-antifield quantization
Recently it was shown how to regularize the Batalin-Vilkovisky (BV)
field-antifield formalism of quantization of gauge theories with the non-local
regularization (NLR) method. The objective of this work is to make an analysis
of the behaviour of this NLR formalism, connected to the BV framework, using
two different regulators: a simple second order differential regulator and a
Fujikawa-like regulator. This analysis has been made in the light of the well
known fact that different regulators can generate different expressions for
anomalies that are related by a local couterterm, or that are equivalent after
a reparametrization. This has been done by computing precisely the anomaly of
the chiral Schwinger model.Comment: 9 pages, Revtex. To appear in Int. J. Mod. Phys.
Non-Linear Supersymmetric -Models and their Gauging in the Atiyah-Ward Space-Time
We present a supersymmetric non-linear \s-model built up in the
superspace of Atiyah-Ward space-time. A manifold of the K\"ahler type comes out
that is restricted by a particular decomposition of the K\"ahler potential. The
gauging of the \s-model isometries is also accomplished in superspace.Comment: 15 pages, Latex, no figure
Dilatonic, Current-Carrying Cosmic String
We study the implications of a scalar-tensorial gravity for the metric of an
isolated self-gravitating superconducting cosmic string. These modifications
are induced by an arbitrary coupling of a massless scalar field to the usual
tensorial field in the gravitational Lagrangian. We derive the metric in the
weak-field approximation and we analyse the behaviour of light in this
spacetime. We end with some discussions.Comment: 12 pp, Latex, no figures, based on a talk given by M. E. X. Guimaraes
at the COSMO 99, 27/9 to 02/10/99, ICTP, Trieste, I
Temperature Measurement and Phonon Number Statistics of a Nanoelectromechanical Resonator
Measuring thermodynamic quantities can be easy or not, depending on the
system that is being studied. For a macroscopic object, measuring temperatures
can be as simple as measuring how much a column of mercury rises when in
contact with the object. At the small scale of quantum electromechanical
systems, such simple methods are not available and invariably detection
processes disturb the system state. Here we propose a method for measuring the
temperature on a suspended semiconductor membrane clamped at both ends. In this
method, the membrane is mediating a capacitive coupling between two
transmission line resonators (TLR). The first TLR has a strong dispersion, that
is, its decaying rate is larger than its drive, and its role is to pump in a
pulsed way the interaction between the membrane and the second TLR. By
averaging the pulsed measurements of the quadrature of the second TLR we show
how the temperature of the membrane can be determined. Moreover the statistical
description of the state of the membrane, which is directly accessed in this
approach is significantly improved by the addition of a Josephson Junction
coupled to the second TLR.Comment: 9 pages, 5 figures. To appear in New Journal of Physic
- …