4,749 research outputs found
Transport in nanoscale systems: the microcanonical versus grand-canonical picture
We analyse a picture of transport in which two large but finite charged
electrodes discharge across a nanoscale junction. We identify a functional
whose minimisation, within the space of all bound many-body wavefunctions,
defines an instantaneous steady state. We also discuss factors that favour the
onset of steady-state conduction in such systems, make a connection with the
notion of entropy, and suggest a novel source of steady-state noise. Finally,
we prove that the true many-body total current in this closed system is given
exactly by the one-electron total current, obtained from time-dependent
density-functional theory.Comment: 6 pages, 1 figur
Rationality of conformally invariant local correlation functions on compactified Minkowski space
Rationality of the Wightman functions is proven to follow from energy
positivity, locality and a natural condition of global conformal invariance
(GCI) in any number D of space-time dimensions. The GCI condition allows to
treat correlation functions as generalized sections of a vector bundle over the
compactification of Minkowski space and yields a strong form of locality valid
for all non-isotropic intervals if assumed true for space-like separations.Comment: 20 pages, LATEX, amsfonts, latexsy
Affine orbifolds and rational conformal field theory extensions of W_{1+infinity}
Chiral orbifold models are defined as gauge field theories with a finite
gauge group . We start with a conformal current algebra A associated
with a connected compact Lie group G and a negative definite integral invariant
bilinear form on its Lie algebra. Any finite group of inner
automorphisms or A (in particular, any finite subgroup of G) gives rise to a
gauge theory with a chiral subalgebra of local
observables invariant under . A set of positive energy
modules is constructed whose characters span, under some assumptions on
, a finite dimensional unitary representation of . We compute
their asymptotic dimensions (thus singling out the nontrivial orbifold modules)
and find explicit formulae for the modular transformations and hence, for the
fusion rules.
As an application we construct a family of rational conformal field theory
(RCFT) extensions of that appear to provide a bridge between two
approaches to the quantum Hall effect.Comment: 64 pages, amste
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