Now showing items 1-20 of 26

  • 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 ...
  • Bouncing loop quantum cosmology from F(T) gravity 

    Amorós Torrent, Jaume; Haro Cases, Jaume; Odintsov, Sergei D. (2013-05)
    Article
    Open Access
    The big bang singularity could be understood as a breakdown of Einstein’s general relativity at very high energies. By adopting this viewpoint, other theories that implement Einstein cosmology at high energies might solve ...
  • Generic behaviour of asymptotically holomorphic Lefschetz pencils 

    Amorós Torrent, Jaume; Muñoz, Vicente; Presas, Francisco (World Scientific, 2005)
    Article
    Open Access
    We prove that the vanishing spheres of the Lefschetz pencils constructed by Donaldson on symplectic manifolds of any dimension are conjugated under the action of the symplectomorphism group of the fiber. More precisely, ...
  • GEOMETRIA DIFERENCIAL 

    Amorós Torrent, Jaume (Universitat Politècnica de Catalunya, 2019-05-21)
    Exam
    Restricted access to the UPC academic community
  • GEOMETRIA DIFERENCIAL 

    Amorós Torrent, Jaume (Universitat Politècnica de Catalunya, 2018-05-01)
    Exam
    Restricted access to the UPC academic community
  • Geometria diferencial | Extraordinari 

    Amorós Torrent, Jaume (Universitat Politècnica de Catalunya, 2019-07-07)
    Exam
    Restricted access to the UPC academic community
  • Geometria diferencial | Final 

    Amorós Torrent, Jaume (Universitat Politècnica de Catalunya, 2019-06-04)
    Exam
    Restricted access to the UPC academic community
  • Nonsingular models of universes in teleparallel theories 

    Haro Cases, Jaume; Amorós Torrent, Jaume (2013-02-14)
    Article
    Open Access
    Different models of universes are considered in the context of teleparallel theories. Assuming that the universe is filled by a fluid with an equation of state P ¼ f ð Þ , for different teleparallel theories ...
  • On the Malcev completion of Kähler groups 

    Amorós Torrent, Jaume (1995)
    Article
    Open Access
  • On the number of defining relations for nonfibered kaehler groups 

    Amorós Torrent, Jaume; Bauer-Catanese, Ingrid (1999-01)
    Article
    Open Access
    We present minimal bounds for the deficiency (least difference between numbers of generators and relations among all presentations of a group) of fundamental groups of quasiprojective manifolds which do not fiber over a ...
  • 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 ...
  • R+\alpha R^2 loop quantum cosmology 

    Amorós Torrent, Jaume; Haro Cases, Jaume; Odintsov, Sergei D. (American Physical Society, 2014-05-06)
    Article
    Open Access
  • R+aR2 loop quantum cosmology 

    Amorós Torrent, Jaume; De Haro, Jaume; Odintsov, Sergei D. (2014-05-06)
    Article
    Open Access
    Working in Einstein frame, we introduce, in order to avoid singularities, holonomy corrections to the f(R)=R+aR2 model. We perform a detailed analytical and numerical study when holonomy corrections are taken into account ...
  • Riemann i les funcions de variable complexa 

    Amorós Torrent, Jaume (2008-02-20)
    Audiovisual
    Open Access
    Conferència enmarcada dintre de la Jornada Riemann
  • Simple inflationary quintessential model 

    Haro Cases, Jaume; Amorós Torrent, Jaume; Pan, Supriya (2016-04-12)
    Article
    Open Access
    In the framework of a flat Friedmann-Lemaitre-Robertson-Walker geometry, we present a nongeodesically past complete model of our Universe without the big bang singularity at finite cosmic time, describing its evolution ...
  • Simple inflationary quintessential model. II. Power law potentials 

    Haro Cases, Jaume; Amorós Torrent, Jaume; Pan, Supriya (American Physical Society, 2016-09-21)
    Article
    Open Access
    The present work is a sequel of our previous work [Phys. Rev. D 93, 084018 (2016)] which depicted a simple version of an inflationary quintessential model whose inflationary stage was described by a Higgs-type potential ...
  • Singular spectrum analysis filtering and Fourier inversion: an efficient and fast way to improve resolution and quality of current density maps with low-cost Hall scanning systems 

    Amorós Torrent, Jaume; Folch Duran, Arnau; Carrera Vilanova, Miquel; López López, José; Granados García, Javier A.J. (2019-01-01)
    Article
    Restricted access - publisher's policy
    Measurement Science and Technology Paper Singular spectrum analysis filtering and Fourier inversion: an efficient and fast way to improve resolution and quality of current density maps with low-cost Hall scanning systems ...
  • Sudden singularities in semiclassical gravity 

    Haro Cases, Jaume; Amorós Torrent, Jaume; Elizalde, Emilio (2012-06-19)
    Article
    Restricted access - publisher's policy
    It has been claimed in a recent paper [J. D. Barrow, A. B. Batista, J. C. Fabris, M. J. S. Houndjo, and G. Dito, Phys. Rev. D 84, 123518 (2011).] that sudden singularities will survive in semiclassical gravity. This issue ...
  • Symplectic Lefschetz fibrations with arbitrary fundamental groups. 

    Amorós Torrent, Jaume; Bogomolov, Fedor; Katzarkov, Ludmil; Pantev, Tony (1998)
    Article
    Open Access
    In this paper we give an explicit costruction of a symplectic Lefschetz fibration whose total space is a smooth compact four dimensional manifold with a prescribed fundamental group. We also study the numerical properties ...
  • The fundamental group of Kaehler manifolds 

    Amorós Torrent, Jaume (1997)
    Article
    Open Access
    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 ...