• Computation of numerical semigroups by means of seeds 

    Bras Amorós, Maria; Fernández González, Julio (2018-09-01)
    Article
    Accés obert
    For the elements of a numerical semigroup which are larger than the Frobenius number, we introduce the definition of seed by broadening the notion of generator. This new concept allows us to explore the semigroup tree in ...
  • 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 ...
  • On elliptic Galois representations and genus-zero modular units 

    Fernández González, Julio; Lario Loyo, Joan Carles (2006-07-03)
    Article
    Accés obert
    Given an odd prime \,$p$\, and a representation $\varrho$\, of the absolute Galois group of a number field $k$ onto $\mathrm{PGL}_2(\mathbb{F}_p)$ with cyclotomic determinant, the moduli space of elliptic curves defined ...
  • El Palau Maricel : un exemple de modernisme a Sitges 

    Fernández González, Julio; Sánchez Fernández, Andrea (Universitat Politècnica de Catalunya, 2010)
    Projecte/Treball Final de Carrera
    Accés obert
    L’objecte d’aquest Projecte Final de Carrera es basa en l’estudi de l’edifici del Palau Maricel, situat a Sitges. Aquest edifici forma part del conjunt de Maricel, que popularment es va dividir en Maricel Mar i Maricel ...
  • Rational points on twists of X0(63) 

    Bruin, Nils; Fernández González, Julio; González i Rovira, Josep; Lario Loyo, Joan Carles (2006-02-07)
    Article
    Accés obert
    Let $\varrho\colon G_\mathbb{Q}\longrightarrow PGL_2(\mathbb{F}_p)$ be a Galois representation with cyclotomic determinant, and let $N>1$ be an integer that is square mod $p$. There exist two twisted modular curves ...
  • Residual ideals of MacLane valuations 

    Fernández González, Julio; Guàrdia Rubies, Jordi; Montes Peral, Jesús; Nart Vinyals, Enric (2015)
    Article
    Accés obert
    Let K be a field equipped with a discrete valuation v. In a pioneering work, MacLane determined all valuations on K(x) extending v. His work was recently reviewed and generalized by Vaqui´e, by using the graded algebra ...
  • 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 ...