Now showing items 1-20 of 27

  • A medial-axis-based model for propagating cracks in a regularised bulk 

    Tamayo Mas, Elena; Rodríguez Ferran, Antonio (John Wiley & Sons, 2015-02-17)
    Article
    Restricted access - publisher's policy
    A new continuous-discontinuous strategy for the simulation of failure is presented. The continuous bulk is regularised by means of a gradient-enhanced damage model, where non-locality is introduced at the level of ...
  • A method to approximate the steepest descent direction of the od matrix adjustment problem 

    Codina Sancho, Esteve; Montero Mercadé, Lídia (Faculdade de Ciencias da Universidade de Lisboa + Universidade dos Açores, 2001)
    Conference report
    Open Access
  • Computing congruences of modular forms and Galois representations modulo prime powers 

    Taixes Ventosa, Xavier; Wiese, Gabor (2010)
    Article
    Open Access
    This article starts a computational study of congruences of modular forms and modular Galois representations modulo prime powers. Algorithms are described that compute the maximum integer modulo which two monic coprime ...
  • Congruences between modular forms and lowering the level mod l^n 

    Dieulefait, Luis Victor; Taixes Ventosa, Xavier (2009)
    Article
    Open Access
    In this article we study the behavior of inertia groups for modular Galois mod ℓn representations and in some cases we give a generalization of Ribet’s lowering the level result.
  • Criptosistema de Lucas 

    Bellot Casanovas, Josep (Universitat Politècnica de Catalunya, 2009-10)
    Master thesis
    Open Access
    En aquest treball es descriuen exhaustivament les funcions de Lucas i el mètode XTR (mètodes de criptogràfics sobre extessions de cossos finits), i s'analitzen tots els algorismes que s'han publicat fins ara per computar ...
  • Dimensionless analysis of HSDM and application to simulation of breakthrough curves of highly adsorbent porous media 

    Pérez Foguet, Agustí; Casoni Rero, Eva; Huerta, Antonio (2013-05)
    Article
    Open Access
    The homogeneous surface diffusion model (HSDM) is widely used for adsorption modeling of aqueous solutions. The Biot number is usually used to characterize model behavior. However, some limitations of this characterization ...
  • Emmy Noether: de l'àlgebra no commutativa a la teoria de nombres 

    Bayer, Pilar (2009-05-06)
    Audiovisual
    Open Access
    En la producció d’EmmyNoetherse solen distingir tres períodes: del 1908 al 1919 en què es dedicà a la teoria d'invariants, teoria de Galois i càlcul de variacions; del 1920 al 1926 en què el seu estudi se centrà en els ...
  • Euler y la Teoría de Números 

    Chamizo, Fernando (2007-02-14)
    Audiovisual
    Open Access
    El gran Euler manifestó su genialidad en muchas áreas de las Matemáticas, entre ellas la teoría de números por la que tuvo un interés continuado a lo largo de su vida. El propósito de esta charla es ilustrar algunas de sus ...
  • Factorization and catenary degree in 3-generated numerical semigroups 

    Aguiló Gost, Francisco de Asis L.; García Sánchez, Pedro A. (2009-08-01)
    Article
    Restricted access - publisher's policy
    Given a numerical semigroup S(A), generated by A = {a,b,N} ⊂ N with 0 < a < b < N and gcd(a,b,N) = 1, we give a parameterization of the set F(m;A) = {(x, y, z) ∈ $N^3$ | xa + yb + zN = m} for any m ∈ S(A). We also give the ...
  • La funció Z de Riemann 

    Quer Bosor, Jordi (2014-01-31)
    Other
    Open Access
    El novembre de 1859 Riemann envià un manuscrit de sis fulls a l’Acadèmia de Berlín titulat Sobre el nombre de primers menors que una quantitat donada, el qual seria l’única publicació dedicada a la teoria de nombres de ...
  • Hamilton y la teoría de Galois 

    Morales Ruíz, Juan José (2006-03-08)
    Audiovisual
    Open Access
    Indudablemente uno de los legados más importantes de Hamilton es la rama de la teoría de ecuaciones diferenciales que en honor a su nombre se denomina Sistemas Hamiltonianos. Ejemplos de sistemas Hamiltonianos son la ...
  • Hybridizable Discontinuous Galerkin with degree adaptivity for the incompressible Navier-Stokes equations 

    Giorgiani, Giorgio; Fernandez Mendez, Sonia; Huerta, Antonio (Elsevier, 2014-07-02)
    Article
    Restricted access - publisher's policy
    A degree adaptive Hybridizable Discontinuous Galerkin (HDG) method for the solution of the incompressible Navier-Stokes equations is presented. The key ingredient is an accurate and computationally inexpensive a posteriori ...
  • La funció Z de Riemann 

    Quer Bosor, Jordi (2007-09-19)
    Audiovisual
    Open Access
    El novembre de 1859 Riemann envià un manuscrit de sis fulls a l’Acadèmia de Berlín titulat Sobre el nombre de primers menors que una quantitat donada, el qual seria l’única publicació dedicada a la teoria de nombres de ...
  • Large graphs of diameter two and given degree 

    Širáň, Jozef; Siagiová, Jana; Ždímalová, Mária (Iniciativa Digital Politècnica, 2011)
    Conference report
    Open Access
    Let r(d, 2), C(d, 2), and AC(d, 2) be the largest order of a regular graph, a Cayley graph, and a Cayley graph of an Abelian group, respectively, of diameter 2 and degree d. The best currently known lower bounds on these ...
  • No anul·lació de funcions L en valors crítics i resultats d'equidistribució en aritmètica 

    Arazo Marín, David (Universitat Politècnica de Catalunya, 2009-10)
    Master thesis
    Open Access
    L'objectiu del treball és revisar els principals resultats d'equidistribució en aritmètica. En primer terme es presenten i demostren el Teorema de densitat de Dirichlet i el Teorema de densitat de Chebotarev. La part central ...
  • Numerical differentiation for local and global tangent operators in computational plasticity 

    Pérez Foguet, Agustí; Rodríguez Ferran, Antonio; Huerta, Antonio (2000)
    Article
    Open Access
    In this paper, numerical di¿erentiation is applied to integrate plastic constitutive laws and to compute the corresponding consistent tangent operators. The derivatives of the constitutive equations are approximated by ...
  • On a question of Sárkozy and Sós for bilinear forms 

    Cilleruelo, Javier; Rué Perna, Juan José (2009-02-02)
    Article
    Restricted access - publisher's policy
    We prove that if 2 ≤ k1 ≤ k2, then there is no infinite sequence $\emph{A}$ of positive integers such that the representation function r(n)=#{(a, a'): n=$k{_1}a$ + $k{_2}a'$, a,a' ∊ $\emph{A}$} is constant for n large ...
  • On elliptic Galois representations and genus-zero modular units 

    Fernández González, Julio; Lario Loyo, Joan Carles (2006-07-03)
    Article
    Open Access
    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 ...
  • On monochromatic solutions of equations in groups 

    Cameron, Peter J.; Cilleruelo, Javier; Serra Albó, Oriol (2006-01-12)
    Article
    Open Access
    Resum no disponible
  • Orders of CM elliptic curves modulo p with at most two primes 

    Iwaniec, Henryk; Jiménez Urroz, Jorge (2006)
    Article
    Open Access
    We prove the analog of Koblitz conjecture when replacing primes by almost prime numbers and considering elliptic curves with complex multiplication. In other words for infinitely many primes $p$, (given in a quantitative ...