Now showing items 85-104 of 211

    • Icon

      Hasse-Schmidt derivations and coefficient fields in positive characteristics  [Article]

      Fernández Lebrón, María Magdalena; Narváez Macarro, Luis (Elsevier, 2003-07-01)
      We show how to express any Hasse-Schmidt derivation of an algebra in terms of a finite number of them under natural hypothesis. As an application, we obtain coefficient fields of the completion of a regular local ring of ...
    • Icon

      Hasse-Schmidt derivations, divided powers and differential smoothness  [Article]

      Narváez Macarro, Luis (Association des Annales de l'Institut Fourier, 2009)
      Let k be a commutative ring, A a commutative k-algebra and D the filtered ring of k-linear differential operators of A. We prove that: (1) The graded ring gr D admits a canonical embedding θ into the graded dual of the ...
    • Icon

      Hironaka's characteristic polygon and effective resolution of surfaces  [Article]

      Piedra Sánchez, Ramón; Tornero Sánchez, José María (Elsevier, 2007-03-01)
      Hironaka’s concept of characteristic polyhedron of a singularity has been one of the most powerful and fruitful ideas of the last decades in singularity theory. In fact, since then combinatorics have become a major tool ...
    • Icon

      Homotopy theory of bicomplexes  [Article]

      Muro Jiménez, Fernando; Roitzheim, Constanze (Elsevier, 2019-05)
      We define two model structures on the category of bicomplexes concentrated in the right half plane. The first model structure has weak equivalences detected by the totalisation functor. The second model structure’s weak ...
    • Icon

      Homotopy theory of non-symmetric operads, II: Change of base category and left properness  [Article]

      Muro Jiménez, Fernando (Mathematical Sciences Publishers, 2014)
      We prove, under mild assumptions, that a Quillen equivalence between symmetric monoidal model categories gives rise to a Quillen equivalence between their model categories of (non-symmetric) operads, and also between model ...
    • Icon

      Homotopy theory of nonsymmetric operads  [Article]

      Muro Jiménez, Fernando (Mathematical Sciences Publishers, 2011)
      We endow categories of nonsymmetric operads with natural model structures. We work with no restriction on our operads and only assume the usual hypotheses for model categories with a symmetric monoidal structure. We also ...
    • Icon

      Homotopy units in A-infinity algebras  [Article]

      Muro Jiménez, Fernando (American Mathematical Society, 2016-03)
      We show that the canonical map from the associative operad to the unital associative operad is a homotopy epimorphism for a wide class of symmetric monoidal model categories. As a consequence, the space of unital associative ...
    • Icon

      How to calculate the slopes of a D-module  [Article]

      Assi, Abdallah; Castro Jiménez, Francisco Jesús; Granger, Michel (Foundation Compositio Mathematica, 1996)
    • Icon

      Improvements of the Weil bound for Artin-Schreier curves  [Article]

      Rojas León, Antonio; Wan, Daqing (Springer, 2011-10)
      For the Artin-Schreier curve y q − y = f(x) defined over a finite field Fq of q elements, the celebrated Weil bound for the number of Fq r -rational points can be sharp, especially in super-singular cases and when r is ...
    • Icon

      Improving an algorithm to solve multiple simultaneous conjugacy problems in braid groups  [Article]

      González-Meneses López, Juan (American Mathematical Society, 2005)
      There are recent cryptographic protocols that are based on Multiple Simultaneous Conjugacy Problems in braid groups. We improve an algorithm, due to Sang Jin Lee and Eonkyung Lee, to solve these problems, by applying a ...
    • Icon

      Inequalities between Littlewood–Richardson coefficients  [Article]

      Bergeron, François; Biagioli, Riccardo; Rosas Celis, Mercedes Helena (Elsevier, 2006-05)
      We prove that a conjecture of Fomin, Fulton, Li, and Poon, associated to ordered pairs of partitions, holds for many infinite families of such pairs. We also show that the bounded height case can be reduced to checking ...
    • Icon

      Integral points in rational polygons: a numerical semigroup approach  [Article]

      Márquez Campos, Guadalupe; Ramírez Alfonsín, Jorge Luis; Tornero Sánchez, José María (Springer, 2016)
      In this paper we use an elementary approach by using numerical semigroups (specifically, those with two generators) to give a formula for the number of integral points inside a right-angled triangle with rational ...
    • Icon

      Invariants and coinvariants of the symmetric group in noncommuting variables  [Article]

      Bergeron, Nantel; Reutenauer, Christophe; Rosas Celis, Mercedes Helena; Zabrocki, Mike (University of Toronto Press, 2008)
      We introduce a natural Hopf algebra structure on the space of noncommutative symmetric functions. The bases for this algebra are indexed by set partitions. We show that there exists a natural inclusion of the Hopf algebra ...
    • Icon

      Irregular hypergeometric D-modules  [Article]

      Fernández Fernández, María Cruz (E, 2010-08-01)
      We study the irregularity of hypergeometric D-modules MA(β) via the explicit construction of Gevrey series solutions along coordinate subspaces in X = C n. As a consequence, we prove that along coordinate hyperplanes the ...
    • Icon

      Irregular modified A-Hypergeometric systems  [Article]

      Castro Jiménez, Francisco Jesús; Fernández Fernández, María Cruz; Koike, Tatsuya; Takayama, Nobuki (American Mathematical Society, 2015)
      A modified A-hypergeometric system is a system of differential equations for the function f(t w · x) where f(y) is a solution of an A-hypergeometric system in n variables and w is an n dimensional integer vector, which is ...
    • Icon

      K-theory of derivators revisited  [Article]

      Muro Jiménez, Fernando; Raptis, George (Mathematical Sciences Publishers, 2017)
      We define a K-theory for pointed right derivators and show that it agrees with Waldhausen K-theory in the case where the derivator arises from a good Waldhausen category. This K-theory is not invariant under general ...
    • Icon

      Katz-Radon transform of l-adic representations  [Article]

      Rojas León, Antonio (Duke University Press, 2012)
      We prove a simple explicit formula for the local Katz-Radon transform of an l-adic representation of the Galois group of the fraction field of a strictly henselian discrete valuation ring with positive residual characteristic, ...
    • Icon

      L-functions of symmetric powers of the generalized Airy family of exponential sums  [Article]

      Haessig, C. Douglas; Rojas León, Antonio (2011-12)
      This paper looks at the L-function of the kth symmetric power of the -sheaf Aif over the affine line associated to the generalized Airy family of exponential sums. Using ℓ-adic techniques, we compute the degree of this ...
    • Icon

      La labor docente del profesor de matemáticas  [Article]

      Aranda Plata, Antonio (Sociedad Española de Matemática Aplicada, 2003)
    • Icon

      Large Galois images for Jacobian varieties of genus 3 curves  [Article]

      Arias de Reyna Domínguez, Sara; Armana, Cécile; Karemaker, Valentijn; Rebolledo, Marusia; Thomas, Lara; Vila Oliva, Núria (Polish Academy of Sciences, Institute of Mathematics, 2016)
      Given a prime number ℓ ≥ 5, we construct an infinite family of three-dimensional abelian varieties over Q such that, for any A/Q in the family, the Galois representation ρA,ℓ : GQ → GSp6 (Fℓ) attached to the ℓ-torsion of ...