284 research outputs found
A residual-based bootstrap test for panel cointegration
We address the issue of panel cointegration testing in dependent panels, showing by simulations that tests based on the stationary bootstrap deliver good size and power performances even with small time and cross-section sample sizes and allowing for a break at a known date. They can thus be an empirically important alternative to asymptotic methods based on the estimation of common factors. Potential extensions include test for cointegration allowing for a break in the cointegrating coefficients at an unknown date
Soft Covariant Gauges on the Lattice
We present an exploratory study of a one-parameter family of covariant,
non-perturbative lattice gauge-fixing conditions, that can be implemented
through a simple Monte Carlo algorithm. We demonstrate that at the numerical
level the procedure is feasible, and as a first application we examine the
gauge dependence of the gluon propagator.Comment: 11 pages, Latex, epsf.sty included + 5 PostScript picture
Theory of Abelian Projection
Analytic methods for Abelian projection are developed. A number of results
are obtained related to string tension measurements. It is proven that even
without gauge fixing, abelian projection yields string tensions of the
underlying non-Abelian theory. Strong arguments are given for similar results
in the case where gauge fixing is employed. The methods used emphasize that the
projected theory is derived from the underlying non-Abelian theory rather than
vice versa. In general, the choice of subgroup used for projection is not very
important, and need not be Abelian. While gauge fixing is shown to be in
principle unnecessary for the success of Abelian projection, it is
computationally advantageous for the same reasons that improved operators,
e.g., the use of fat links, are advantageous in Wilson loop measurements. Two
other issues, Casimir scaling and the conflict between projection and critical
universality, are also discussed.Comment: Minor corrections, new section added, 14 pages, 3 figures, RevTe
Periódicos cientÃficos digitais e ontologia : uma pesquisa
Apresenta pesquisa sobre periódicos cientÃficos digitais e a construção de ontologia de referência, identificando a importância dos mesmos como veÃculos propulsores das ciências, seu formato digital e sua interoperabilidade. Trata-se de uma pesquisa documental e experimental, objetivando desenvolver uma ontologia que padronize os elementos (metadados) essenciais que estruturam, criam e mantém um periódico cientÃfico. Identificaram-se ontologias que tratam de periódicos cientÃficos e compilaram-se os elementos tratados nessas ontologias, comparando-os com estudos existentes sobre a criação e manutenção de periódicos cientÃficos. Conclui-se com uma lista de metadados que estruturam periódicos cientÃficos, sendo que os termos foram traduzidos para o inglês e relacionam-se sinônimos, os quais estão sendo inseridos em editor de ontologias - plataforma Protégé
Nonperturbative Gauge Fixing and Perturbation Theory
We compare the gauge-fixing approach proposed by Jona-Lasinio and Parrinello,
and by Zwanziger (JPLZ) with the standard Fadeev-Popov procedure, and
demonstrate perturbative equality of gauge-invariant quantities, up to
irrelevant terms induced by the cutoff. We also show how a set of local,
renormalizable Feynman rules can be constructed for the JPLZ procedure.Comment: 9 pages, latex, version to appear in Phys. Rev.
Responsabilidade Financeira e Criminal pelos Dinheiros Públicos – Tutela dos Direitos Constitucionais Fundamentais Sociais
The implementation of the Constitutional Social Fundamental Rights is one way to proceed. It is necessary, appropriate and proportionate, following the constitutional principles (constitutional) transparency and responsiveness to the demands of the population, accountability and self-responsibility. All this also involves the development of constitutional principles that are anti-corruption. The financial and criminal liability could constitute an incentive to improve the management of public funds and the enhanced enforcement of fundamental constitutional principles. The constitutional, administrative, criminal areas, public management and administration and good governance science, should be articulated in a single strategy. Federal Court / Constitutional, Supreme / High Court of Justice or audit offices have to be considered together. Courts which should be alert to the management of taxpayers resources and the debt of public authorities and public companies. Courts which should be alert to the management of taxpayers resources and indebtedness of governments. Debts even have implications for national sovereignty and relations with external creditors. It is important to manage with competence and honesty public money. We can not forget, in parallel, of necessity, appropriateness and proportionality of the existence of an effective criminal responsibility and appropriate means to recover public assets, aimed at achieving the Social Fundamental Constitutional Rights in countries like Portugal or Brazil, which have been irregularly diverted to serve private interests.A concretização dos Direitos Constitucionais Fundamentais Sociais é um caminho a prosseguir. É necessário, adequado e proporcional, seguir os princÃpios constitucionais (constitucionais) da transparência e da responsividade à s demandas da população, da prestação de contas e própria responsabilidade. Tudo isto também envolve o desenvolvimento de princÃpios constitucionais que sejam de anticorrupção. A responsabilidade financeira e criminal pode constituir um incentivo à melhoria da gestão dos dinheiros públicos e a uma melhor efetivação dos princÃpios constitucionais fundamentais. As áreas constitucional, administrativa, penal, de gestão pública e de ciência de administração e boa governança, devem ser articuladas numa só estratégia. Tribunal Federal/Constitucional, Supremo/Superior Tribunal de Justiça ou Tribunais de Contas têm que ser considerados em conjunto. Tribunais os quais devem estar atentos à gestão dos recursos dos contribuintes e ao endividamento dos poderes públicos e das empresas públicas. DÃvidas que, inclusive, têm implicaç.es na soberania nacional e nas relaç.es com os credores externos. É importante gerir com competência e honestidade os dinheiros públicos. N.o se pode esquecer, de modo paralelo, da necessidade, adequação e proporcionalidade da existência duma responsabilidade criminal eficaz e por meios adequados à recuperação de activos públicos, dirigidos à concretização dos Direitos Constitucionais Fundamentais Sociais em paÃses como Portugal ou o Brasil, que tenham sido irregularmente desviados para servir interesses privados
Problems in Lattice Gauge Fixing
We review many topics and results about numeric gauge fixing in lattice QCD.Comment: 47 pages, 16 eps figures. Review article sent to IJMP
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