5,730 research outputs found
Convergence of numerical schemes for short wave long wave interaction equations
We consider the numerical approximation of a system of partial differential
equations involving a nonlinear Schr\"odinger equation coupled with a
hyperbolic conservation law. This system arises in models for the interaction
of short and long waves. Using the compensated compactness method, we prove
convergence of approximate solutions generated by semi-discrete finite volume
type methods towards the unique entropy solution of the Cauchy problem. Some
numerical examples are presented.Comment: 31 pages, 7 figure
Thermodynamics of quantum crystalline membranes
We investigate the thermodynamic properties and the lattice stability of
two-dimensional crystalline membranes, such as graphene and related compounds,
in the low temperature quantum regime . A key role is played by
the anharmonic coupling between in-plane and out-of plane lattice modes that,
in the quantum limit, has very different consequences than in the classical
regime. The role of retardation, namely of the frequency dependence, in the
effective anharmonic interactions turns out to be crucial in the quantum
regime. We identify a crossover temperature, , between classical and
quantum regimes, which is K for graphene. Below , the
heat capacity and thermal expansion coefficient decrease as power laws with
decreasing temperature, tending to zero for as required by the
third law of thermodynamics.Comment: 13 pages, 1 figur
Reply to 'Comment on "Thermodynamics of quantum crystalline membranes"'
In this note, we reply to the comment made by E.I.Kats and V.V.Lebedev
[arXiv:1407.4298] on our recent work "Thermodynamics of quantum crystalline
membranes" [Phys. Rev. B 89, 224307 (2014)]. Kats and Lebedev question the
validity of the calculation presented in our work, in particular on the use of
a Debye momentum as a ultra-violet regulator for the theory. We address and
counter argue the criticisms made by Kats and Lebedev to our work.Comment: 5 pages, 4 figure
Axial Anomaly from the BPHZ regularized BV master equation
A BPHZ renormalized form for the master equation of the field antifiled (or
BV) quantization has recently been proposed by De Jonghe, Paris and Troost.
This framework was shown to be very powerful in calculating gauge anomalies. We
show here that this equation can also be applied in order to calculate a global
anomaly (anomalous divergence of a classically conserved Noether current),
considering the case of QED. This way, the fundamental result about the
anomalous contribution to the Axial Ward identity in standard QED (where there
is no gauge anomaly) is reproduced in this BPHZ regularized BV framework.Comment: 10 pages, Latex, minor changes in the reference
Noncommutative Particles in Curved Spaces
We present a formulation in a curved background of noncommutative mechanics,
where the object of noncommutativity is considered as an
independent quantity having a canonical conjugate momentum. We introduced a
noncommutative first-order action in D=10 curved spacetime and the covariant
equations of motions were computed. This model, invariant under diffeomorphism,
generalizes recent relativistic results.Comment: 1+15 pages. Latex. New comments and results adde
Characterization of a rare analphoid supernumerary marker chromosome in mosaic
Abstract publicado em: Chromosome Research. 2015;23(Suppl 1):67-8. doi:10.1007/s10577-015-9476-6Analphoid supernumerary marker chromosomes (SMCs) are a rare subclass of SMCs C-band-negative
and devoid of alpha-satellite DNA. These marker chromosomes cannot be identified unambiguously by conventional banding techniques alone being necessary to apply molecular cytogenetic methods in favour of a detailed characterization. In this work we report an analphoid SMC involving the terminal long arm of chromosome 7, in 9 years-old boy with several dysmorphic features and severe development delay.
Cytogenetic analysis revealed a mosaic karyotype with the presence of an extra SMC, de novo, in 20 %
of lymphocytes and 73 % of fibroblast cells. FISH analysis with alpha-satellite probes for all chromosomes, whole chromosome painting probe for chromosome 7, and D7S427 and TelVysion 7q probes, allowed
establishing the origin of the SMC as an analphoidmarker resulting of an invdup rearrangement of 7q36-qter region. Affimetrix CytoScan HD microarray analysis, redefined the SMC to arr[hg19] 7q35(143696249-159119707)×2~3, which correspond to a gain of 15.42 Mb and encloses 67 OMIM genes, 16 of which are associated to disease. This result, combined with detailed clinical description, will provide an important means for better genotype-phenotype correlation and a more suitable genetic counselling to the patient and his parents, despite the additional difficulty resulting from being a mosaic (expression varies in different tissues). Analphoid SMCs derived from chromosome 7 are very rare, with only three cases reported so far. With this case we hope contribute to a better understanding of this type of chromosome rearrangements which are difficult for genetic counselling
Hamiltonian embedding of the massive noncommutative U(1) theory
We show that the massive noncommutative U(1) can be embedded in a gauge
theory by using the BFFT Hamiltonian formalism. By virtue of the peculiar
non-Abelian algebraic structure of the noncommutative massive U(1) theory,
several specific identities involving Moyal commutators had to be used in order
to make the embedding possible. This leads to an infinite number of steps in
the iterative process of obtaining first-class constraints. We also shown that
the involutive Hamiltonian can be constructed.Comment: 8 pages, Revtex (multicol
HERA-B Framework for Online Calibration and Alignment
This paper describes the architecture and implementation of the HERA-B
framework for online calibration and alignment. At HERA-B the performance of
all trigger levels, including the online reconstruction, strongly depends on
using the appropriate calibration and alignment constants, which might change
during data taking. A system to monitor, recompute and distribute those
constants to online processes has been integrated in the data acquisition and
trigger systems.Comment: Submitted to NIM A. 4 figures, 15 page
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