9,560 research outputs found

    Who cried for Argentina? Notes on the 2001-02 Crisis

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    In the midst of the current global slowdown this paper revisits Argentina’s dismal experience in the 1990s with a complete embrace of globalisation, the crisis of 2001-02 and its subsequent recovery.Argentine; Economic; Crisis;

    The role of the Beltrami parametrization of complex structures in 2-d Free Conformal Field Theory

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    This talk gives a review on how complex geometry and a Lagrangian formulation of 2-d conformal field theory are deeply related. In particular, how the use of the Beltrami parametrization of complex structures on a compact Riemann surface fits perfectly with the celebrated locality principle of field theory, the latter requiring the use infinite dimensional spaces. It also allows a direct application of the local index theorem for families of elliptic operators due to J.-M. Bismut, H. Gillet and C. Soul\'{e}. The link between determinant line bundles equipped with the Quillen\'s metric and the so-called holomorphic factorization property will be addressed in the case of free spin jj b-c systems or more generally of free fields with values sections of a holomorphic vector bundles over a compact Riemann surface.Comment: Actes du Colloque "Complex Geometry '98

    Improved Epstein-Glaser Renormalization II. Lorentz invariant framework

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    The Epstein--Glaser type T-subtraction introduced by one of the authors in a previous paper is extended to the Lorentz invariant framework. The advantage of using our subtraction instead of Epstein and Glaser's standard W-subtraction method is especially important when working in Minkowski space, as then the counterterms necessary to keep Lorentz invariance are simplified. We show how T-renormalization of primitive diagrams in the Lorentz invariant framework directly relates to causal Riesz distributions. A covariant subtraction rule in momentum space is found, sharply improving upon the BPHZL method for massless theories.Comment: LaTeX, 15 pages, no figure. Version to be published in J. Math. Phys. (Section 7 on the Massive Case and some references have been withdrawn). To the Memory of Laurent Schwart

    Gauge field theories: various mathematical approaches

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    This paper presents relevant modern mathematical formulations for (classical) gauge field theories, namely, ordinary differential geometry, noncommutative geometry, and transitive Lie algebroids. They provide rigorous frameworks to describe Yang-Mills-Higgs theories or gravitation theories, and each of them improves the paradigm of gauge field theories. A brief comparison between them is carried out, essentially due to the various notions of connection. However they reveal a compelling common mathematical pattern on which the paper concludes.Comment: 33 pages. To be published in the book: Mathematical Structures of the Universe (Copernicus Center Press, Krak\'ow, Poland, 2014

    Local description of generalized forms on transitive Lie algebroids and applications

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    In this paper we study the local description of spaces of forms on transitive Lie algebroids. We use this local description to introduce global structures like metrics, \ast-Hodge operation and integration along the algebraic part of the transitive Lie algebroid (its kernel). We construct a \v{C}ech-de Rham bicomplex with a Leray-Serre spectral sequence. We apply the general theory to Atiyah Lie algebroids and to derivations on a vector bundle
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