13,752 research outputs found
A relativistic superalgebra in a generalized Schroedinger picture
We consider a relativistic superalgebra in the picture in which the time and
spatial derivative cannot be presented in the operators of the particle. The
supersymmetry generators as well as the Hamilton operators for the massive
relativistic particles with spin zero and spin-1/2 are expressed in terms of
the principal series of the unitary representations of the Lorentz group. We
also consider the massless case. New Hamilton operators are conctructed for the
massless particles with spin zero and spin 1/2.Comment: 7 page
One particle quantum equation in a de Sitter spacetime
We consider a free particle in a de Sitter spacetime. We use a picture in
which the analogs of the Schr\"odinger operators of the particle are
independent of both the time and the space coordinates. These operators induce
operators which are related to Killing vectors of the de Sitter spacetime.Comment: 12 page
Test of Conformal Invariance in One-Dimensional Quantum Liquid with Long-Range Interaction
We numerically study the momentum distribution of one-dimensional Bose and
Fermi systems with long-range interaction for the ``special'' values
, singled out by random matrix theory. The critical
exponents are shown to be independent of density and in excellent agreement
with estimates obtained from conformal finite-size scaling analysis.Comment: 25 page
Numerical investigations of scaling at the Anderson transition
At low temperature T, a significant difference between the behavior of
crystals on the one hand and disordered solids on the other is seen:
sufficiently strong disorder can give rise to a transition of the transport
properties from conducting behavior with finite resistance R to insulating
behavior with R=infinity as T -> 0. This well-studied phenomenon is called the
disorder-driven metal-insulator transition and it is characteristic to
non-crystalline solids. In this review of recent advances, we have presented
results of transport studies in disordered systems, ranging from modifications
of the standard Anderson model of localization to effects of a two-body
interaction. Of paramount importance in these studies was always the highest
possible accuracy of the raw data combined with the careful subsequent
application of the finite-size scaling technique. In fact, it is this scaling
method that has allowed numerical studies to move beyond simple extrapolations
and reliably construct estimates of quantities as if one were studying an
infinite system.Comment: 18 pages, 6 figures, "The Anderson Transition and its
Ramifications-Localisation, Quantum Interference, and Interactions", 'Lecture
Notes in Physics' series, ed. T. Brandes and S. Kettemann, Springer Verlag,
to be publishe
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