Now showing items 41-60 of 211

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      Conjugacy in Garside groups II: Structure of the ultra summit set  [Article]

      Birman, Joan S.; Gebhardt, Volker; González-Meneses López, Juan (European Mathematical Society, 2008)
      This paper is the second in a series in which the authors study the conjugacy decision problem (CDP) and the conjugacy search problem (CSP) in Garside groups. The ultra summit set USS(X) of an element X in a Garside group ...
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      Conjugacy in Garside Groups III: Periodic braids  [Article]

      Birman, Joan S.; Gebhardt, Volker; González-Meneses López, Juan (Elsevier, 2007-10-15)
      An element in Artin’s braid group Bn is said to be periodic if some power of it lies in the center of Bn. In this paper we prove that all previously known algorithms for solving the conjugacy search problem in Bn are ...
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      Conjugacy problem for braid groups and Garside groups  [Article]

      Gonçalves Soares Franco, Nuno María; González-Meneses López, Juan (Elsevier, 2003-08-01)
      We present a new algorithm to solve the conjugacy problem in Artin braid groups, which is faster than the one presented by Birman, Ko and Lee. This algorithm can be applied not only to braid groups, but to all Garside ...
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      Conservation of the noetherianity by perfect transcendental field extensions  [Article]

      Fernández Lebrón, María Magdalena; Narváez Macarro, Luis (European Mathematical Society, 2003)
      Let k be a perfect field of characteristic p>0, k(t)per the perfect closure of k(t) and A a k-algebra. We characterize whether the ring A⊗kk(t)per is noetherian when A is the ring of formal power series in n indeterminates over k.
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      Constructions in R[x_1, ..., x_n]. Applications to K-Theory  [Article]

      Gago Vargas, Manuel Jesús (2002-06-25)
      A classical result in K-Theory about polynomial rings like the Quillen-Suslin theorem admits an algorithmic approach when the ring of coefficients has some computational properties, associated with Gröbner bases. There ...
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      Continuous division of differential operators  [Article]

      Hauser, Herwig; Narváez Macarro, Luis (Association des Annales de l'Institut Fourier, 2001)
      In this paper, we give a new proof of the continuity of division by differential operators with analytic coefficients, originally proved by Mebkhout and the second author. Our methods come from the proof of the Constant ...
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      Continuous division of linear differential operators and faithful flatness of D∞X over DX  [Article]

      Narváez Macarro, Luis; Rojas León, Antonio (Société Mathématique de France, 2004)
      In these notes we prove the faithful flatness of the sheaf of infinite order linear differential operators over the sheaf of finite order linear differential operators on a complex analytic manifold. We give the ...
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      Correspondance de Howe explicite: paires duales de type II  [Article]

      Mínguez Espallargas, Alberto (Société Mathématique de France, 2008)
      Dans cet article, nous proposons une nouvelle méthode pour démontrer la bijectivité de la correspondance de Howe pour les paires duales du type (GLn, GLm) sur un corps F localement compact non archimédien. La preuve est ...
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      Correspondance de Jacquet-Langlands locale et congruences modulo l  [Article]

      Mínguez Espallargas, Alberto; Sécherre, Vincent (Springer, 2017-05)
      Let F be a non-Archimedean local field of residual characteristic p, and be a prime number different from p. We consider the local Jacquet-Langlands correspondence between -adic discrete series of GLn(F) and an inner form ...
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      Cylinders for non-symmetric DG-operads via homological perturbation theory  [Article]

      Muro Jiménez, Fernando (Elsevier, 2016-09)
      We construct small cylinders for cellular non-symmetric DG-operads over an arbitrary commutative ring by using the basic perturbation lemma from homological algebra. We show that our construction, applied to the A-infinity ...
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      Decomposing Jacobians of curves over finite fields in the absence of algebraic structure  [Article]

      Ahmadi, Omran; McGuire, Gary; Rojas León, Antonio (Elsevier, 2015-11)
      We consider the issue of when the L-polynomial of one curve over Fq divides the L-polynomial of another curve. We prove a theorem which shows that divisibility follows from a hypothesis that two curves have the same number ...
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      Dual Garside structure and reducibility of braids  [Article]

      Calvez, Matthieu (Elsevier, 2012-04-15)
      Benardete, Gutierrez and Nitecki showed an important result which relates the geometrical properties of a braid, as a homeomorphism of the punctured disk, to its algebraic Garside-theoretical properties. Namely, they showed ...
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      Dualité et comparaison sur les complexes de de Rham logarithmiques par rapport aux diviseurs libres  [Article]

      Calderón Moreno, Francisco Javier; Narváez Macarro, Luis (Association des Annales de l'Institut Fourier, 2005)
      Let X be a complex analytic manifold and D \subset X a free divisor. Integrable logarithmic connections along D can be seen as locally free {\cal O}_X-modules endowed with a (left) module structure over the ring of logarithmic ...
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      Dwyer-Kan homotopy theory of enriched categories  [Article]

      Muro Jiménez, Fernando (London Mathematical Society, 2015)
      We construct a model structure on the category of small categories enriched over a combinatorial closed symmetric monoidal model category satisfying the monoid axiom. Weak equivalences are Dwyer–Kan equivalences, i.e. ...
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      Echelons of power series and Gabrielov’s counterexample to nested linear Artin Approximation  [Article]

      Alonso García, María Emilia; Castro Jiménez, Francisco Jesús; Hauser, Herwig; Koutschan, Christoph (London Mathematical Society, 2018)
      Gabrielov’s famous example for the failure of analytic Artin approximation in the presence of nested subring conditions is shown to be due to a growth phenomenon in standard basis computations for echelons, a generalization ...
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      En recuerdo de Alexander Grothendieck: prólogo para una lectura de su vida y obra  [Article]

      Narváez Macarro, Luis (Real Sociedad Matemática Española, 2017)
      En este artículo repasamos algunas de las claves de las contribuciones matemáticas de Alexander Grothendieck y del contexto en el que se gestaron, y nos asomamos así a la vida y obra de una de las figuras más influyentes ...
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      Encoding algebraic power series  [Article]

      Alonso García, María Emilia; Castro Jiménez, Francisco Jesús; Hauser, Herwig (Springer, 2017)
      The division algorithm for ideals of algebraic power series satisfying Hironaka’s box condition is shown to be finite when expressed suitably in terms of the defining polynomial codes of the series. In particular, the codes ...
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      Entrevista a Isabel Fernández, conferenciante invitada al ICM 2010  [Article]

      Muro Jiménez, Fernando (Real Sociedad Matematica Española, 2010)
      Isabel Fernández, de la Universidad de Sevilla, es conferenciante invitada junto con Pablo Mira (Universidad Politécnica de Cartagena) a la sección de Geometría del próximo ICM, que se celebrará en agosto en Hyderabad ...
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      Equimultiple locus of embedded algebroid surfaces and blowing-up in arbitrary characteristic  [Article]

      Piedra Sánchez, Ramón; Tornero Sánchez, José María (Chinese Academy of Sciences, 2009-12)
      This paper extends previous results of the authors, concerning the behaviour of the equimultiple locus of algebroid surfaces under blowing–up, to arbitrary characteristic.
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      Equimultiple locus of embedded algebroid surfaces and blowing-up in characteristic zero  [Article]

      Piedra Sánchez, Ramón; Tornero Sánchez, José María (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences, 2004)
      The smooth equimultiple locus of embedded algebroid surfaces appears naturally in many resolution process, both classical and modern.In this paper we explore how it changes by blowing–up.