Restrictions over two-dimensional gauge models with Thirring-like interaction

Some years ago, it was shown how fermion self-interacting terms of the Thirring-type impact the usual structure of massless two-dimensional gauge theories [1]. In that work only the cases of pure vector and pure chiral gauge couplings have been considered and the corresponding Thirring term was also pure vector and pure chiral respectively, such that the vector ( or chiral) Schwinger model should not lose its chirality structure due to the addition of the quartic interaction term. Here we extend this analysis to a generalized vector and axial coupling both for the gauge interaction and the quartic fermionic interactions. The idea is to perform quantization without losing the original structure of the gauge coupling. In order to do that we make use of an arbitrariness in the definition of the Thirring-like interaction.

Operator ordering in quantum radiative processes

In this work we reexamine quantum electrodynamics of atomic electrons in the Coulomb gauge in the dipole approximation and calculate the shift of atomic energy levels in the context of Dalibard, Dupont-Roc and Cohen-Tannoudji formalism by considering the variation rates of physical observable. We then analyze the physical interpretation of the ordering of operators in the dipole approximation interaction Hamiltonian in terms of field fluctuations and self-reaction of atomic electrons, discussing the arbitrariness in the statistical functions in second-order bound-state perturbation theory. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Predictive formulation of the Nambu-Jona-Lasinio model

A novel strategy to handle divergences typical of perturbative calculations is implemented for the Nambu-Jona-Lasinio model and its phenomenological consequences investigated. The central idea of the method is to avoid the critical step involved in the regularization process, namely, the explicit evaluation of divergent integrals. This goal is achieved by assuming a regularization distribution in an implicit way and making use, in intermediary steps, only of very general properties of such regularization. The finite parts are separated from the divergent ones and integrated free from effects of the regularization. The divergent parts are organized in terms of standard objects, which are independent of the ( arbitrary) momenta running in internal lines of loop graphs. Through the analysis of symmetry relations, a set of properties for the divergent objects are identified, which we denominate consistency relations, reducing the number of divergent objects to only a few. The calculational strategy eliminates unphysical dependencies of the arbitrary choices for the routing of internal momenta, leading to ambiguity-free, and symmetry-preserving physical amplitudes. We show that the imposition of scale properties for the basic divergent objects leads to a critical condition for the constituent quark mass such that the remaining arbitrariness is removed. The model becomes predictive in the sense that its phenomenological consequences do not depend on possible choices made in intermediary steps. Numerical results are obtained for physical quantities at the one-loop level for the pion and sigma masses and pion-quark and sigma-quark coupling constants.

Dynamics of the deconfinement transition

We estimate the dissipation coefficient Γ that appears in Ginzburg-Landau-Langevin equations that describe phenomenologically the deconfinement transition in QCD. This is done through the implementation of Glauber dynamics of pure SU(3) lattice gauge theory. The coefficient Γ is extracted from the short-time exponential growth of the equal time correlation function of the order parameter. Although the absolute determination of Γ is ambiguous due to the difficulties in relating real time and Monte Carlo time, its relative temperature dependence can be obtained with much less arbitrariness. © 2007 American Institute of Physics.

Comunicação sinestésica midiática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O poeta enquanto vidente: Novalis e a romantização da linguagem

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O símbolo e a alegoria nos textos teóricos de Goethe [de 1772 a 1798]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intelectuais, literatura e imprensa no pós-golpe

Culture and the arts in Brazil were impacted directly by the military coup from 1964 onwards. In spite of repression and censorship, the activity of intellectuals and artists in the pre-1964 period was not interrupted nor became stagnant, but gained even greater force due to the presence of control and restrictions by the institutions of repression over against the freedom of creation and thought. As in many sectors of cultural production, literature played a vigorously combative role against the arbitrariness of the regime and implemented “projects of resistance” on the basis of key elements of representation. This occurred, for instance, through the writing and circulation of works such as Pessach: a travessia, by journalist Carlos Heitor Cony, and Quarup, by journalist Antonio Callado. The two novels enabled a broad debate on the narrative form and the scope of involvement in the literature of the 1960s, such as the confrontation between Paulo Francis and Ferreira Gullar in the pages of Revista Civilização Brasileira, which is the focus of this article.

A marginalizacao que a privatizacao promove

When people are put aside in the society we have what is called as social marginalization. However there is a wider or even severe marginalization, i. e., the state marginalization, which is the difficulty of the citizen to recognize himself in the state. What is intended here is to identify the main features of such marginalization, its effects upon the state itself and the possible means to overcome it. In order to fulfill this aim it is taken what it is considered to be a meaningfull manifestation of the state marginalization, that is the privatization of public services. These services are usually free but it does not mean that they cost nothing because they are granted by the payment of taxes and so can be at the disposal of everyone. When these services are dealt by the private initiative then a barrier is build and many can only continue to have what should be their right if they pay more than they already do with the taxes. As an example of it we have the privatization of many highways in the state of São Paulo. A certain comunity reacted towards it but all the questions were dismissed AURORA ano V número 9 - DEZEMBRO DE 2011 ISSN: 1982-8004 http://www2.marilia.unesp.br/revistas/índex.php/aurora/. 166 by the authorities as something impossible to solve. The contradictions between the private and the public interests were solved by the legal formality but they show themselves to be expression of arbitrariness and indetermination. One comes to the conclusion that the privatization is the identification of the State with the bourgeois and civil society that turns the public thing into a private thing. Despite of all this and also because of all this the recovered knowledge about the meaning of the State and the exposition of this new marginalization may promote an ongoing striving towards a necessary mobilizing process.

Educação, Estado e Poder: o ensino médio em debate na Revista Brasileira de Estudos Pedagógicos (1962-1972)

Pós-graduação em Educação - FFC