Now showing items 1-12 of 86

  • Xiao's conjecture for general fibred surfaces 

    Barja Yáñez, Miguel Ángel; González Alonso, Víctor; Naranjo Del val, Joan Carles (2018-06-01)
    Article
    Open Access
    We prove that the genus g, the relative irregularity qf and the Clifford index cf of a non-isotrivial fibration f satisfy the inequality qf=g-cf. This gives in particular a proof of Xiao’s conjecture for fibrations whose ...
  • Poles of the complex zeta function of a plane curve 

    Blanco Fernández, Guillem (2019-07-09)
    Article
    Open Access
  • A Koszul complex over skew polynomial rings 

    Álvarez Montaner, Josep; Boix, Alberto F.; Zarzuela Armengou, Santiago (2019-01-01)
    Article
    Restricted access - publisher's policy
    We construct a Koszul complex in the category of left skew polynomial rings associated with a flat endomorphism that provides a finite free resolution of an ideal generated by a Koszul regular sequence
  • Coupling symmetries with Poisson structures 

    Miranda Galcerán, Eva; Laurent Gengoux, Camille (Springer, 2013)
    Article
    Restricted access - publisher's policy
    We study local normal forms for completely integrable systems on Poisson manifolds in the presence of additional symmetries. The symmetries that we consider are encoded in actions of compact Lie groups. The existence of ...
  • The clay public lecture and conference on the Poincaré Conjecture, Paris, 7-9 June 2010 

    Miranda Galcerán, Eva (2010-09)
    Article
    Open Access
  • On the volume elements of a manifold with transverse zeroes 

    Miranda Galcerán, Eva; Cardona Aguilar, Robert (Springer, 2019)
    Article
    Open Access
    Moser proved in 1965 in his seminal paper [15] that two volume forms on a compact manifold can be conjugated by a diffeomorphism, that is to say they are equivalent, if and only if their associated cohomology classes in ...
  • Bouncing cosmologies via modified gravity in the ADM formalism: Application to loop quantum cosmology 

    Haro Cases, Jaume; Amorós Torrent, Jaume (American Physical Society (APS), 2018-03-15)
    Article
    Open Access
    We consider the Arnowitt-Deser-Misner formalism as a tool to build bouncing cosmologies. In this approach, the foliation of the spacetime has to be fixed in order to go beyond general relativity modifying the gravitational ...
  • Decomposition spaces and restriction species 

    Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (Oxford University Press, 2018-09-12)
    Article
    Restricted access - publisher's policy
    We show that Schmitt’s restriction species (such as graphs, matroids, posets, etc.) naturally induce decomposition spaces (a.k.a. unital 2-Segal spaces), and that their associated coalgebras are an instance of the general ...
  • Qualitative study in loop quantum cosmology 

    Aresté Saló, Llibert; Amorós Torrent, Jaume; Haro Cases, Jaume (2017-12-07)
    Article
    Restricted access - publisher's policy
    This work contains a detailed qualitative analysis, in general relativity and in loop quantum cosmology, of the dynamics in the associated phase space of a scalar field minimally coupled with gravity, whose potential mimics ...
  • Convexity for Hamiltonian torus actions on b-symplectic manifolds 

    Guillemin, Victor; Miranda Galcerán, Eva; Pires, Ana Rita; Scott, Geoffrey (2017)
    Article
    Open Access
    n [GMPS] we proved that the moment map image of a b-symplectic toric manifold is a convex b-polytope. In this paper we obtain convexity results for the more general case of non-toric hamiltonian torus actions on b-symplectic ...
  • The eventual paracanonical map of a variety of maximal Albanese dimension 

    Barja Yáñez, Miguel Ángel; Pardini, Rita; Stoppino, Lidia (2019)
    Article
    Open Access
    Let Xbe a smooth complex projective variety such that the Albanese map of Xis generically ¿nite onto its image. Here we study the so-called eventual m-paracanonical map of X, whose existence is implied by the results of ...
  • Remarks on multisymplectic reduction 

    Echeverría Enríquez, Arturo; Muñoz Lecanda, Miguel Carlos; Román Roy, Narciso (2018-06-01)
    Article
    Restricted access - publisher's policy
    The problem of reduction of multisymplectic manifolds by the action of Lie groups is stated and discussed, as a previous step to give a fully covariant scheme of reduction for classical field theories with symmetries.