Ara es mostren els items 1-14 de 14

    • A Weierstrass extremal field theory for the fractional Laplacian 

      Cabré Vilagut, Xavier; Urtiaga Erneta, Iñigo; Felipe Navarro, Juan Carlos (De Gruyter, 2023-10-27)
      Article
      Accés restringit per política de l'editorial
      In this paper, we extend, for the first time, part of the Weierstrass extremal field theory in the Calculus of Variations to a nonlocal framework. Our model case is the energy functional for the fractional Laplacian (the ...
    • An overview of the Hamilton–Jacobi theory: the classical and geometrical approaches and some extensions and applications 

      Román Roy, Narciso (Multidisciplinary Digital Publishing Institute (MDPI), 2021-01-01)
      Article
      Accés obert
      This work is devoted to review the modern geometric description of the Lagrangian and Hamiltonian formalisms of the Hamilton–Jacobi theory. The relation with the “classical” Hamiltonian approach using canonical transformations ...
    • Constraint algorithm for singular field theories in the k-cosymplectic framework 

      Gràcia Sabaté, Francesc Xavier; Rivas Guijarro, Xavier; Román Roy, Narciso (American Institute of Mathematical Sciences, 2020-03-15)
      Article
      Accés obert
      The aim of this paper is to develop a constraint algorithm for singular classical field theories in the framework of k-cosymplectic geometry. Since these field theories are singular, we need to introduce the notion of ...
    • Deformaciones miniversales de parejas de tensores de segundo orden 

      Clotet Juan, Josep; Magret Planas, Maria dels Dolors; Peña Carrera, Marta (Universidad de Sevilla, 2007-09)
      Text en actes de congrés
      Accés obert
      Consideramos en el espacio de parejas de tensores tension y deformacion la relacion de equivalencia que se corresponde con cambios de base ortonormales. Identificandolas con parejas de matrices cuadradas, podemos utilizar ...
    • Erratum: constraint algorithm for singular field theories in the $ k $-cosymplectic framework 

      Gràcia Sabaté, Francesc Xavier; Rivas Guijarro, Xavier; Román Roy, Narciso (AMER INST MATHEMATICAL SCIENCES-AIMS, 2021-06)
      Article
      Accés obert
    • Global block-similarity and pole assignment of class C<sup>p</sup> 

      Ferrer Llop, Josep; Puerta Sales, Ferran (1998)
      Article
      Accés obert
      Starting from the existence of a $C^{p}$-basis for any $C^{p}$-family of subspaces having constant dimension, we construct a Brunovsky basis of class $C^{p}$ for a $C^{p}$-family of pairs of matrices having constant ...
    • Grups de matrius 

      Pijuan Casanova, Pau (Universitat Politècnica de Catalunya, 2014-07)
      Treball Final de Grau
      Accés obert
      S'estudien els grups de matrius clàssics com per exemple el grup lineal, el grup ortogonal, el grup unitari o el grup simplectic, amb la finalitat d'introduir els grups de Lie.
    • Hamilton-Jacobi theory in multisymplectic classical field theories 

      De León, Manuel; Prieto Martínez, Pedro Daniel; Román Roy, Narciso; Vilariño Fernández, Silvia (2017-09-01)
      Article
      Accés obert
      The geometric framework for the Hamilton-Jacobi theory developed in the studies of Carinena et al. [Int. J. Geom. Methods Mod. Phys. 3(7), 1417-1458 (2006)], Carinena et al. [Int. J. Geom. Methods Mod. Phys. 13(2), 1650017 ...
    • Multisymplectic Lagrangian and Hamiltonian formalisms of classical field theories 

      Román Roy, Narciso (2009)
      Article
      Accés obert
      This review paper is devoted to presenting the standard multisymplectic formulation for describing geometrically classical field theories, both the regular and singular cases. First, the main features of the Lagrangian ...
    • On some aspects of the geometry of non integrable distributions and applications 

      Muñoz Lecanda, Miguel Carlos (American Institute of Mathematical Sciences, 2018-12-01)
      Article
      Accés obert
      We consider a regular distribution D in a Riemannian manifold (M, g). The LeviCivita connection on (M, g) together with the orthogonal projection allow to endow the space of sections of D with a natural covariant derivative, ...
    • Singularities for a fully non-linear elliptic equation in conformal geometry 

      González Nogueras, María del Mar; Mazzieri, Lorenzo (2014)
      Article
      Accés obert
    • Skinner–Rusk formalism for k-contact systems 

      Gràcia Sabaté, Francesc Xavier; Rivas Guijarro, Xavier; Román Roy, Narciso (2022-02-01)
      Article
      Accés obert
      In previous papers, a geometric framework has been developed to describe non-conservative field theories as a kind of modified Lagrangian and Hamiltonian field theories. This approach is that of k-contact Hamiltonian ...
    • Spatial estimates for Kelvin-Voigt finite elasticity with nonlinear viscosity: well behaved solutions in space. 

      Quintanilla de Latorre, Ramón; Saccomandi, Giuseppe (2020-11)
      Article
      Accés obert
      We provide some spatial estimates for the nonlinear partial di erential equation governing anti-plane motions in a nonlinear viscoelastic theory of Kelvin-Voigt type when the viscosity is a function of the strain rate. The ...
    • The fundamental group of Kaehler manifolds 

      Amorós Torrent, Jaume (1997)
      Article
      Accés obert
      It studies the fundamental group of complex algebraic varieties, in its Betti, Hodge and de Rham realizations. This study has been carried out both in the absolute case, i.e. fundamental groups of such varieties, and in ...