14,942 research outputs found
Three dimensional Lifshitz black hole and the Korteweg-de Vries equation
We consider a solution of three dimensional New Massive Gravity with a
negative cosmological constant and use the AdS/CTF correspondence to inquire
about the equivalent two dimensional model at the boundary. We conclude that
there should be a close relation with the Korteweg-de Vries equation.Comment: 4 page
Experience with the Open Source based implementation for ATLAS Conditions Data Management System
Conditions Data in high energy physics experiments is frequently seen as
every data needed for reconstruction besides the event data itself. This
includes all sorts of slowly evolving data like detector alignment, calibration
and robustness, and data from detector control system. Also, every Conditions
Data Object is associated with a time interval of validity and a version.
Besides that, quite often is useful to tag collections of Conditions Data
Objects altogether. These issues have already been investigated and a data
model has been proposed and used for different implementations based in
commercial DBMSs, both at CERN and for the BaBar experiment. The special case
of the ATLAS complex trigger that requires online access to calibration and
alignment data poses new challenges that have to be met using a flexible and
customizable solution more in the line of Open Source components. Motivated by
the ATLAS challenges we have developed an alternative implementation, based in
an Open Source RDBMS. Several issues were investigated land will be described
in this paper:
-The best way to map the conditions data model into the relational database
concept considering what are foreseen as the most frequent queries.
-The clustering model best suited to address the scalability problem.
-Extensive tests were performed and will be described.
The very promising results from these tests are attracting the attention from
the HEP community and driving further developments.Comment: 8 pages, 4 figures, 3 tables, conferenc
Newtonian Perturbations on Models with Matter Creation
Creation of Cold Dark Matter (CCDM) can macroscopically be described by a
negative pressure, and, therefore, the mechanism is capable to accelerate the
Universe, without the need of an additional dark energy component. In this
framework we discuss the evolution of perturbations by considering a
Neo-Newtonian approach where, unlike in the standard Newtonian cosmology, the
fluid pressure is taken into account even in the homogeneous and isotropic
background equations (Lima, Zanchin and Brandenberger, MNRAS {\bf 291}, L1,
1997). The evolution of the density contrast is calculated in the linear
approximation and compared to the one predicted by the CDM model. The
difference between the CCDM and CDM predictions at the perturbative
level is quantified by using three different statistical methods, namely: a
simple -analysis in the relevant space parameter, a Bayesian
statistical inference, and, finally, a Kolmogorov-Smirnov test. We find that
under certain circumstances the CCDM scenario analysed here predicts an overall
dynamics (including Hubble flow and matter fluctuation field) which fully
recovers that of the traditional cosmic concordance model. Our basic conclusion
is that such a reduction of the dark sector provides a viable alternative
description to the accelerating CDM cosmology.Comment: Physical Review D in press, 10 pages, 4 figure
Density-functionals not based on the electron gas: Local-density approximation for a Luttinger liquid
By shifting the reference system for the local-density approximation (LDA)
from the electron gas to other model systems one obtains a new class of density
functionals, which by design account for the correlations present in the chosen
reference system. This strategy is illustrated by constructing an explicit LDA
for the one-dimensional Hubbard model. While the traditional {\it ab initio}
LDA is based on a Fermi liquid (the electron gas), this one is based on a
Luttinger liquid. First applications to inhomogeneous Hubbard models, including
one containing a localized impurity, are reported.Comment: 4 pages, 4 figures (final version, contains additional applications
and discussion; accepted by Phys. Rev. Lett.
Международный культурно-академический обмен: опыт личного и научного роста
В этой статье описывается опыт трех студентов, участвовавших в программе международной академической мобильности в рамках специальности Металлургическое машиностроение. Это отчет о пребывании студентов в России в Уральском федеральном университете, который стал возможным благодаря Федеральному университету Оуро Прето (UFOP) и Совету по международным делам (CAINT). Обмен, который проходил с начала февраля до конца июля, стал возможностью для приобретения новых научных, культурных и социальных знаний, в том числе знаний в области бизнеса, экономики и менеджмента. Надеемся на стимулирование специальности «Международная мобильность» на высшем уровне, в виду ее важности для улучшения академического образования и повышения уровня подготовки выпускников из Бразилии путем научного и культурного обмена.This article has objective describe an experience of three students to integrate a program of International Mobility Academic, during the graduate in Metallurgical Engineering. It is an account of students experience at Russia, at Ural Federal University, made possible by Federal University of Ouro Preto – (UFOP) and Coordinating international affairs – (CAINT). The exchange experience, that is preview to have started on February and end on July, had possibility the acquisition of new scientific knowledge, cultural and social, including learning Business, Economic and Management. As a contribution, hope to stimulate and intensify the International Mobility specialty in the ambit of graduate, considering the it important to improvement of academic education and the excellence on superior graduate Brazilian by scientific exchange and culture on exterior
Solos e aptidão agrícola das terras cultivadas com cajueiro no Estado do Maranhão.
Situacao, limites e extensao; clima; geologia; quartenario; terciario;cretaceo; triasico; permiano; pre-cambriano indiviso; vegetacao; floresta caducifolia; floresta subcaducifolia/caducifolia; floresta subcaducifolia; floresta subperenifolia; cerrados; restingas e dunas; relevo;chapadas altas; chapadas baixas; superficies suave-onduladas; grande baixada maranhense; tabuleiros costeiros; restingas e dunas costeiras; estudo de campo; analise do solo; solos; criterios para estabelecimento e subdivisao das classes de solos e fases empregadas; descricao das classes de solos; aptdao agricola da terra para o cajueiro.bitstream/CNPAT-2010/4781/1/Bp-021.pd
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