Now showing items 1-20 of 40

    • A Koszul complex over skew polynomial rings 

      Álvarez Montaner, Josep; Boix, Alberto F.; Zarzuela Armengou, Santiago (2019-01-01)
      Article
      Open Access
      We construct a Koszul complex in the category of left skew polynomial rings associated with a flat endomorphism that provides a finite free resolution of an ideal generated by a Koszul regular sequence
    • Addendum to "Frobenius and Cartier algebras of Stanley-Reisner rings" [J.Algebra 358 (2012), 162-177] 

      Álvarez Montaner, Josep; Yanagawa, Kohji (2013-05)
      External research report
      Open Access
      We give a purely combinatorial characterization of complete Stanley-Reisner rings having a principally generated (equivalently, nitely generated) Cartier algebra
    • Addendum to “Frobenius and Cartier algebras of Stanley–Reisner rings” [J. Algebra 358 (2012) 162–177] 

      Álvarez Montaner, Josep; Yanagawa, Kohji (2014-09)
      Article
      Restricted access - publisher's policy
      We give a purely combinatorial characterization of complete Stanley–Reisner rings having a principally generated (equivalently, finitely generated) Cartier algebra.
    • Characteristic cycle of local cohomology modules of monomial ideals II 

      Álvarez Montaner, Josep (2003)
      Article
      Open Access
    • Characteristic cycles of local cohomology modules of monomial ideals 

      Álvarez Montaner, Josep (1998)
      Article
      Open Access
      By using the theory of D-modules we express the characteristic cycle of a local cohomology module supported on a monomial ideal in terms of conormal bundles relative to a subvariety. As a consequence we can decide when a ...
    • Characteristic cycles of localizations: algorithmic approach 

      Álvarez Montaner, Josep; Leykin, Anton (2004)
      Article
      Open Access
      For a polynomial ring R = k[x1, ..., xn], we present an algorithm for computing the characteristic cycle of the localization Rf for any nonzero polynomial f ∈ R. The approach is useful to answer certain questions regarding ...
    • Cohomología local con soporte un ideal monomial (D-módulos y combinatoria) 

      Álvarez Montaner, Josep (2000)
      Article
      Open Access
      We study, by using the theory of algebraic $\cD$-modules, the local cohomology modules supported on a monomial ideal $I$ of the polynomial ring $R=k[x_1,\dots,x_n]$, where $k$ is a field of characteristic zero. We compute ...
    • Computing jumping numbers and multiplier ideals in two-dimensional regular local rings 

      Alberich Carramiñana, Maria; Álvarez Montaner, Josep; Dachs Cadefau, Ferran (Universitat de Barcelona. Edicions i Publicacions, 2014)
      Conference report
      Restricted access - publisher's policy
      We give a new algorithm that computes the jumping numbers with their multiplicities and multiplier ideals of any ideal in a regular two-dimensional local ring.
    • Constancy regions of mixed multiplier ideals in two-dimensional local rings with rational singularities 

      Alberich Carramiñana, Maria; Álvarez Montaner, Josep; Dachs Cadefau, Ferran (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2018)
      Article
      Open Access
      The aim of this paper is to study mixed multiplier ideals associated with a tuple of ideals in a two-dimensional local ring with a rational singularity. We are interested in the partition of the real positive orthant given ...
    • D-modules, Bernstein-Sato polynomials and F-invariants of direct summands 

      Álvarez Montaner, Josep; Huneke, Craig; Núñez-Betancourt, Luis (2017-12-01)
      Article
      Open Access
      We study the structure of D -modules over a ring R which is a direct sum- mand of a polynomial or a power series ring S with coefficients over a field. We relate properties of D -modules over R to D -modules over S . We ...
    • Effective computation of base points of ideals in two-dimensional local rings 

      Alberich Carramiñana, Maria; Álvarez Montaner, Josep; Blanco Fernández, Guillem (2018-01-04)
      Article
      Open Access
      © 2018 Elsevier Ltd. We provide an algorithm that allows to describe the minimal log-resolution of an ideal in a smooth complex surface from the minimal log-resolution of its generators. In order to make this algorithm ...
    • Frobenius and Cartier algebras of Stanley-Reisner rings 

      Álvarez Montaner, Josep; Boix, Alberto F.; Zarzuela Armengou, Santiago (2011-09)
      External research report
      Open Access
      We study the generation of the Frobenius algebra of the injective hull of a complete Stanley-Reisner ring over a field with positive characteristic. In particular, by extending the ideas used by M. Katzman to give a ...
    • Frobenius and Cartier algebras of Stanley-Reisner rings 

      Álvarez Montaner, Josep; Boix, Alberto F.; Zarzuela Armengou, Santiago (2011-05-15)
      Article
      Restricted access - publisher's policy
      We study the generation of the Frobenius algebra of the injective hull of a complete Stanley–Reisner ring over a field with positive characteristic. In particular, by extending the ideas used by M. Katzman to give a ...
    • Generating functions associated to Frobenius algebras 

      Álvarez Montaner, Josep (Elsevier, 2019-12-01)
      Article
      Restricted access - publisher's policy
      We introduce a generating function associated to the homogeneous gen-erators of a graded algebra that measures how far is this algebra from being finitelygenerated. For the case of some algebras of Frobenius endomorphisms ...
    • Generators of D-modules in positive characteristic 

      Álvarez Montaner, Josep; Blickle, Manuel; Lyubeznik, Gennady (2004)
      Article
      Open Access
      Let R = k[x1, . . . , xd] or R = k[[x1, . . . , xd]] be either a polynomial or a formal power series ring in a finite number of variables over a field k of characteristic p > 0 and let DR|k be the ring of klinear differential ...
    • GEOMETRÍA AFÍ I EUCLIDIANA 

      Álvarez Montaner, Josep (Universitat Politècnica de Catalunya, 2017-07-05)
      Exam
      Restricted access to the UPC academic community
    • GEOMETRÍA AFÍ I EUCLIDIANA 

      Álvarez Montaner, Josep (Universitat Politècnica de Catalunya, 2017-04-03)
      Exam
      Restricted access to the UPC academic community
    • GEOMETRÍA AFÍ I EUCLIDIANA 

      Álvarez Montaner, Josep (Universitat Politècnica de Catalunya, 2017-06-09)
      Exam
      Restricted access to the UPC academic community
    • Linearization of local cohomology modules 

      Álvarez Montaner, Josep; Zarzuela Armengou, Santiago (American Mathematical Society, 2003)
      Part of book or chapter of book
      Open Access
      The aim of this work is to describe the linear structure of regular holonomic $\mathcal D$-modules with support a normal crossing with variation zero introduced in [Local cohomology, arrangements of subspaces and monomial ...
    • Local cohomology of binomial edge ideals and their generic initial ideals 

      Álvarez Montaner, Josep (2019-01-01)
      Article
      Restricted access - publisher's policy
      We provide a Hochster type formula for the local cohomology modules of binomial edge ideals. As a consequence we obtain a simple criterion for the Cohen–Macaulayness and Buchsbaumness of these ideals and we describe their ...