Ara es mostren els items 1-11 de 11

  • Automorphism group of split Cartan modular curves 

    González Rovira, Josep (2016-08-01)
    Article
    Accés obert
  • Constraints on the automorphism group of a curve 

    González Rovira, Josep (2017-01-01)
    Article
    Accés obert
    For a curve of genus > 1 defined over a finite field, we present a sufficient criterion for the non-existence of automorphisms of order a power of a rational prime. We show how this criterion can be used to determine the ...
  • Cropping Euler factors of modular L-functions 

    González Rovira, Josep; Jiménez Urroz, Jorge; Lario Loyo, Joan Carles (2013-09)
    Article
    Accés obert
    According to the Birch and Swinnerton-Dyer conjectures, if A/Q is an abelian variety, then its L-function must capture a substantial part of the properties of A. The smallest number field L where A has all its endomorphisms ...
  • Equations of bielliptic modular curves 

    González Rovira, Josep (2012-11)
    Article
    Accés obert
    We give a procedure to determine equations for the modular curves X0(N) which are bielliptic and equations for the 30 values of N such that X0(N) is bielliptic and nonhyperelliptic are presented.
  • Frobenius distribution for quotients of Fermat curves of prime exponent 

    Fité, Francesc; González Rovira, Josep; Lario Loyo, Joan Carles (2015-06-18)
    Article
    Accés obert
    Let C denote the Fermat curve over Q of prime exponent l. The Jacobian Jac(C) of C splits over Q as the product of Jacobians Jac(C_k), 0< k < l-1, where C_k are curves obtained as quotients of C by certain subgroups of ...
  • Functions and differentials on the non-split Cartan modular curve of level 11 

    Fernández González, Julio; González Rovira, Josep (2017-01-01)
    Article
    Accés obert
    The genus 4 modular curve Xns(11) attached to a non-split Cartan group of level 11 admits a model defined over Q. We compute generators for its function field in terms of Siegel modular functions. We also show that its ...
  • Nonexistence of almost Moore digraphs of diameter four 

    Conde Colom, Josep; Gimbert Quintilla, Joan; González Rovira, Josep; Miret Biosca, Josep Maria; Moreno Chiral, Ramiro (2013-03-31)
    Article
    Accés obert
    Regular digraphs of degree d > 1, diameter k > 1 and order N(d; k) = d+ +dk will be called almost Moore (d; k)-digraphs. So far, the problem of their existence has only been solved when d = 2; 3 or k = 2; 3. In this ...
  • On the nonexistence of almost Moore digraphs 

    Conde Colom, Josep; Gimbert Quintilla, Joan; González Rovira, Josep; Miller, Mirka; Miret Biosca, Josep Maria (2014-07-01)
    Article
    Accés restringit per política de l'editorial
    Digraphs of maximum out-degree at most d > 1, diameter at most k > 1 and order N(d, k) = d + ... + d(k) are called almost Moore or (d, k)-digraphs. So far, the problem of their existence has been solved only when d = 2, 3 ...
  • The automorphism group of the non-split Cartan modular curve of level 11 

    Dose, Valerio; Fernández González, Julio; González Rovira, Josep; Schoof, Rene (2014-11-01)
    Article
    Accés restringit per política de l'editorial
    We derive equations for the modular curve X-ns(11) associated to a non-split Cartan subgroup of GL(2)(F-11). This allows us to compute the automorphism group of the curve and show that it is isomorphic to Klein's four ...
  • The Frobenius traces distribution for modular Abelian surfaces 

    González Rovira, Josep (2014-02)
    Article
    Accés restringit per política de l'editorial
    We prove that there exist at least 15 pairs of measures for which the two normalized Frobenius traces on modular Abelian surfaces are equidistributed. Under an assumption about stochastic independence, we prove that there ...
  • The kernel of Ribet’s isogeny for genus three Shimura curves 

    Molina Blanco, Santiago; González Rovira, Josep (2015)
    Article
    Accés obert
    There are exactly nine reduced discriminants D of indefinite quaternion algebras over Q for which the Shimura curve XD attached to D has genus 3. We present equations for these nine curves. Moreover, for each D we determine ...