Now showing items 1-12 of 150

    • An inextensible model for the robotic manipulation of textiles 

      Coltraro Ianniello, Franco; Amorós Torrent, Jaume; Alberich Carramiñana, Maria; Torras, Carme (2022-01-01)
      Article
      Open Access
      We introduce a new isometric strain model for the study of the dynamics of cloth garments in a moderate stress environment, such as robotic manipulation in the neighborhood of humans. This model treats textiles as surfaces ...
    • An open set of 4×4 embeddable matrices whose principal logarithm is not a Markov generator 

      Casanellas Rius, Marta; Fernández Sánchez, Jesús; Roca Lacostena, Jordi (Taylor & Francis, 2020-12-17)
      Article
      Open Access
      A Markov matrix is embeddable if it can represent a homogeneous continuous-time Markov process. It is well known that if a Markov matrix has real and pairwise-different eigenvalues, then the embeddability can be determined ...
    • The groupoid of finite sets is biinitial in the 2-category of rig categories 

      Elgueta Montó, Josep (2021-11-01)
      Article
      Restricted access - publisher's policy
      The groupoid of finite sets has a “canonical” structure of a symmetric 2-rig with the sum and product respectively given by the coproduct and product of sets. This 2-rig ^ FSet is just one of the many non-equivalent ...
    • A K-contact Lagrangian formulation for nonconservative field theories 

      Gaset Rifà, Jordi; Gràcia Sabaté, Francesc Xavier; Muñoz Lecanda, Miguel Carlos; Rivas Guijarro, Xavier; Román Roy, Narciso (2021-06-01)
      Article
      Restricted access - publisher's policy
      Dynamical systems with dissipative behaviour can be described in terms of contact manifolds and a modified version of Hamilton's equations. Dissipation terms can also be added to field equations, as showed in a recent paper ...
    • Skinner–Rusk formalism for k-contact systems 

      Gràcia Sabaté, Francesc Xavier; Rivas Guijarro, Xavier; Román Roy, Narciso (2022-02-01)
      Article
      Open Access
      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 ...
    • Regular local rings of dimension four and Gorenstein syzygetic prime ideals 

      Planas Vilanova, Francesc d'Assís (Elsevier, 2022-07-01)
      Article
      Restricted access - publisher's policy
      Let R be a Noetherian local ring. We prove that R is regular of dimension at most 4 if, and only if, every prime ideal, defining a Gorenstein quotient ring, is syzygetic. We deduce a characterization of these rings in terms ...
    • Slope inequalities for fibrations of non-maximal Albanese dimension 

      Barja Yáñez, Miguel Ángel (2021-06-15)
      Article
      Restricted access - publisher's policy
      We study and obtain Slope inequalities for fibred irregular varieties of non-maximal Albanese dimension. We give a comparison theorem between Clifford–Severi and Slope inequalities for this type of fibrations. We also ...
    • The second-order problem for k-presymplectic Lagrangian field theories: application to the Einstein–Palatini model 

      Adame Carrillo, David; Gaset Rifà, Jordi; Román Roy, Narciso (springer-Verlag, 2022-01-01)
      Article
      Open Access
      In general, the system of 2nd-order partial differential equations made of the Euler–Lagrange equations of classical field theories are not compatible for singular Lagrangians. This is the so-called second-order problem. ...
    • Turing universality of the incompressible Euler equations and a conjecture of Moore 

      Cardona Aguilar, Robert; Miranda Galcerán, Eva; Peralta-Salas, Daniel (2021-08-24)
      Article
      Restricted access - publisher's policy
      In this article, we construct a compact Riemannian manifold of high dimension on which the time-dependent Euler equations are Turing complete. More precisely, the halting of any Turing machine with a given input is equivalent ...
    • Integrable systems on singular symplectic manifolds: from local to global 

      Cardona Aguilar, Robert; Miranda Galcerán, Eva (2021-09-22)
      Article
      Restricted access - publisher's policy
      In this article, we consider integrable systems on manifolds endowed with symplectic structures with singularities of order one. These structures are symplectic away from a hypersurface where the symplectic volume goes ...
    • Bernstein-Sato functional equations, v -filtrations, and multiplier ideals of direct summands 

      Álvarez Montaner, Josep; Hernández, Daniel J.; Jeffries, Jack; Núñez-Betancourt, Luis; Teixeira, Pedro; Witt, Emily E. (2021-01-01)
      Article
      Open Access
      This paper investigates the existence and properties of a Bernstein– Sato functional equation in nonregular settings. In particular, we construct D-modules in which such formal equations can be studied. The existence of ...
    • Constrained Lagrangian dissipative contact dynamics 

      de León Rodríguez, Manuel; Lainz Valcázar, Manuel; Muñoz Lecanda, Miguel Carlos; Román Roy, Narciso (2021-12-28)
      Article
      Restricted access - publisher's policy
      We show that the contact dynamics obtained from the Herglotz variational principle can be described as a constrained nonholonomic or vakonomic ordinary Lagrangian system depending on a dissipative variable with an adequate ...