1,172 research outputs found
Comparing Fifty Natural Languages and Twelve Genetic Languages Using Word Embedding Language Divergence (WELD) as a Quantitative Measure of Language Distance
We introduce a new measure of distance between languages based on word
embedding, called word embedding language divergence (WELD). WELD is defined as
divergence between unified similarity distribution of words between languages.
Using such a measure, we perform language comparison for fifty natural
languages and twelve genetic languages. Our natural language dataset is a
collection of sentence-aligned parallel corpora from bible translations for
fifty languages spanning a variety of language families. Although we use
parallel corpora, which guarantees having the same content in all languages,
interestingly in many cases languages within the same family cluster together.
In addition to natural languages, we perform language comparison for the coding
regions in the genomes of 12 different organisms (4 plants, 6 animals, and two
human subjects). Our result confirms a significant high-level difference in the
genetic language model of humans/animals versus plants. The proposed method is
a step toward defining a quantitative measure of similarity between languages,
with applications in languages classification, genre identification, dialect
identification, and evaluation of translations
The effect of sublattice symmetry breaking on the electronic properties of a doped graphene
Motivated by a number of recent experimental studies, we have carried out the
microscopic calculation of the quasiparticle self-energy and spectral function
in a doped graphene when a symmetry breaking of the sublattices is occurred.
Our systematic study is based on the many-body GW approach that is
established on the random phase approximation and on graphene's massive Dirac
equation continuum model. We report extensive calculations of both the real and
imaginary parts of the quasiparticle self-energy in the presence of a gap
opening. We also present results for spectral function, renormalized Fermi
velocity and band gap renormalization of massive Dirac Fermions over a broad
range of electron densities. We further show that the mass generating in
graphene washes out the plasmaron peak in spectral weight.Comment: 22 Pages, 10 Figure
Comparative study of screened inter-layer interactions in the Coulomb drag effect in bilayer electron systems
Coulomb drag experiments in which the inter-layer resistivity is measured are
important as they provide information on the Coulomb interactions in bilayer
systems. When the layer densities are low correlation effects become
significant to account for the quantitative description of experimental
results. We investigate systematically various models of effective inter-layer
interactions in a bilayer system and compare our results with recent
experiments. In the low density regime, the correlation effects are included
via the intra- and inter-layer local-field corrections. We employ several
theoretical approaches to construct static local-field corrections. Our
comparative study demonstrates the importance of including the correlation
effects accurately in the calculation of drag resistivity. Recent experiments
performed at low layer densities are adequately described by effective
inter-layer interactions incorporating static correlations.Comment: Final Version. To appear in Phys. Rev.
Theory of correlations in strongly interacting fluids of two-dimensional dipolar bosons
Ground-state properties of a two-dimensional fluid of bosons with repulsive
dipole-dipole interactions are studied by means of the Euler-Lagrange
hypernetted-chain approximation. We present a self-consistent semi-analytical
theory of the pair distribution function and ground-state energy of this
system. Our approach is based on the solution of a zero-energy scattering
Schr\"{o}dinger equation for the "pair amplitude" with an
effective potential from Jastrow-Feenberg correlations. We find excellent
agreement with quantum Monte Carlo results over a wide range of coupling
strength, nearly up to the critical coupling for the liquid-to-crystal quantum
phase transition. We also calculate the one-body density matrix and related
quantities, such as the momentum distribution function and the condensate
fraction.Comment: 8 pages, 8 figures, submitte
Effective electron-electron interactions and magnetic phase transition in a two-dimensional electron liquid
Cataloged from PDF version of article.We investigate the spin-dependent effective electron-electron interactions in a uniform system of two-dimensional electrons to understand the spontaneous magnetization expected to occur at very low density. For this purpose, we adopt the Kukkonen-Overhauser form for the effective interactions which are built by accurately determined local-field factors describing the charge and spin fluctuations. The critical behavior of the effective interaction for parallel spin electrons allows us to quantitatively locate the transition to the ferromagnetic state at r(s) approximate to 27. When the finite width effects are approximately taken into account the transition occurs at r(s) approximate to 30 in agreement with recent quantum Monte Carlo calculations. (C) 2007 Elsevier Ltd. All rights reserved
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