19,904 research outputs found
Space-time defects :Domain walls and torsion
The theory of distributions in non-Riemannian spaces is used to obtain exact
static thin domain wall solutions of Einstein-Cartan equations of gravity.
Curvature -singularities are found while Cartan torsion is given by
Heaviside functions. Weitzenb\"{o}ck planar walls are caracterized by torsion
-singularities and zero curvature. It is shown that Weitzenb\"{o}ck
static thin domain walls do not exist exactly as in general relativity. The
global structure of Weitzenb\"{o}ck nonstatic torsion walls is investigated.Comment: J.Math.Phys.39,(1998),Jan. issu
Mass Generation from Lie Algebra Extensions
Applied to the electroweak interactions, the theory of Lie algebra extensions
suggests a mechanism by which the boson masses are generated without resource
to spontaneous symmetry breaking. It starts from a gauge theory without any
additional scalar field. All the couplings predicted by the Weinberg-Salam
theory are present, and a few others which are nevertheless consistent within
the model.Comment: 11 pages; revtex; title and PACS have been changed; comments included
in the manuscrip
Geometric Phase for Fermionic Quasiparticles Scattering by Disgyration in Superfluids
We consider a Volovik's analog model for description of a topological defects
in a superfluid and we investigate the scattering of quasiparticles in this
background. The analog of the gravitational Aharonov-Bohm in this system is
found. An analysis of this problem employing loop variables is considered and
corroborates for the existence of the Aharonov-Bohm effect in this system. The
results presented here may be used to study the Aharonov-Bohm effect in
superconductors.Comment: 7 pages, to appear in Europhys. Let
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