12,445 research outputs found
The residue current of a codimension three complete intersection
Let , , and be holomorphic functions on a complex manifold
and assume that the common zero set of the has maximal codimension, i.e.,
that it is a complete intersection. We prove that the iterated Mellin transform
of the residue integral has an analytic continuation to a neighborhood of the
origin in . We prove also that the natural regularization of the
residue current converges unrestrictedly
Relating Turing's Formula and Zipf's Law
An asymptote is derived from Turing's local reestimation formula for
population frequencies, and a local reestimation formula is derived from Zipf's
law for the asymptotic behavior of population frequencies. The two are shown to
be qualitatively different asymptotically, but nevertheless to be instances of
a common class of reestimation-formula-asymptote pairs, in which they
constitute the upper and lower bounds of the convergence region of the
cumulative of the frequency function, as rank tends to infinity. The results
demonstrate that Turing's formula is qualitatively different from the various
extensions to Zipf's law, and suggest that it smooths the frequency estimates
towards a geometric distribution.Comment: 9 pages, uuencoded, gzipped PostScript; some typos remove
A pullback operation on a class of currents
For any holomorphic map between a complex manifold and a
complex Hermitian manifold we extend the pullback from smooth forms
to a class of currents in a cohomologically sound way. We provide a basic
calculus for this pullback. The class of currents we consider contains in
particular the Lelong current of any analytic cycle. Our pullback depends in
general on the Hermitian structure of but coincides with the usual pullback
of currents in case is a submersion. The construction is based on the Gysin
mapping in algebraic geometry.Comment: Theorem 1.2 is improve
Tagging the Teleman Corpus
Experiments were carried out comparing the Swedish Teleman and the English
Susanne corpora using an HMM-based and a novel reductionistic statistical
part-of-speech tagger. They indicate that tagging the Teleman corpus is the
more difficult task, and that the performance of the two different taggers is
comparable.Comment: 14 pages, LaTeX, to appear in Proceedings of the 10th Nordic
Conference of Computational Linguistics, Helsinki, Finland, 199
Full counting statistics of incoherent Andreev transport
We study the full counting statistics of heterostructures consisting of
normal metal parts connected to a superconducting terminal. Assuming that
coherent superconducting correlations are suppressed in the normal metals we
show, using Keldysh-Nambu Green's functions, that the system can be mapped onto
a purely normal system with twice the number of elements. For a superconducting
beam splitter with several normal terminals we obtain general results for the
counting statistics.Comment: 7 pages, submitted to Europhys. Let
Proposal for non-local electron-hole turnstile in the Quantum Hall regime
We present a theory for a mesoscopic turnstile that produces spatially
separated streams of electrons and holes along edge states in the quantum Hall
regime. For a broad range of frequencies in the non-adiabatic regime the
turnstile operation is found to be ideal, producing one electron and one hole
per cycle. The accuracy of the turnstile operation is characterized by the
fluctuations of the transferred charge per cycle. The fluctuations are found to
be negligibly small in the ideal regime.Comment: 4+ pages, 2 figure
- …