7,971 research outputs found
RANDOM MATRIX THEORY APPROACH TO THE INTENSITY DISTRIBUTIONS OF WAVES PROPAGATING IN A RANDOM MEDIUM
Full text linkStatistical properties of coherent radiation propagating in a quasi - 1D
random media is studied in the framework of random matrix theory. Distribution
functions for the total transmission coefficient and the angular transmission
coefficient are obtained.Comment: 8 pages, latex, no figures. Submitted to Phys.Rev.
Rational, Replacement, and Local Invariants of a Group Action
Full text linkThe paper presents a new algorithmic construction of a finite generating set
of rational invariants for the rational action of an algebraic group on the
affine space. The construction provides an algebraic counterpart of the moving
frame method in differential geometry. The generating set of rational
invariants appears as the coefficients of a Groebner basis, reduction with
respect to which allows to express a rational invariant in terms of the
generators. The replacement invariants, introduced in the paper, are tuples of
algebraic functions of the rational invariants. Any invariant, whether
rational, algebraic or local, can be can be rewritten terms of replacement
invariants by a simple substitution.Comment: 37 page
Itinerant Ferromagnetism in the electronic localization limit
Full text linkWe present Hall effect, , and magnetoresistance, ,
measurements of ultrathin films of Ni, Co and Fe with thicknesses varying
between 0.2-8 nm and resistances between 1 M - 100 Both
measurements show that films having resistance above a critical value, ,
(thickness below a critical value, ) show no signs for ferromagnetism.
Ferromagnetism appears only for films with , where is material
dependent. We raise the possibility that the reason for the absence of
spontaneous magnetization is suppression of itinerant ferromagnetism by
electronic disorder in the strong localization regime.Comment: 4 pages, 4 figure
Logarithmic Currents in the SU(2)_0 WZNW model
Get PDFWe study four point correlation functions of the spin 1 operators in the
SU(2)_0 WZNW model. The general solution which is everywhere single-valued has
logarithmic terms and thus has a natural interpretation in terms of logarithmic
conformal field theory. These are not invariant under all the crossing
symmetries but can remain if fields possess additional quantum numbers.Comment: 11 pages. Minor correction
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