Now showing items 1-8 of 8

  • Dynamics of Many-Body Quantum Systems 

    Giménez Grau, Aleix (Universitat Politècnica de Catalunya, 2015-07-03)
    Bachelor thesis
    Open Access
    We study the ground state and the excitations of quantum bose systems. The hypernetted chain equations (HNC) are introduced and we show that the methods based on them produce acceptable approximations of the static structure ...
  • Growth of sobolev norms for the cubic defocusing NLS with a convolution potential 

    Guàrdia Munarriz, Marcel (2014-03-16)
    Article
    Open Access
    Fix s > 1. Colliander et al. proved in (Invent Math 181:39–113, 2010 )the existence of solutions of the cubic defocusing nonlinear Schrödinger equation in the two torus whose s -Sobolev norm undergoes arbitrarily large ...
  • Kirchhoff indexes of a network 

    Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel; Mitjana Riera, Margarida (Elsevier, 2010-04-15)
    Article
    Restricted access - publisher's policy
    In this work we define the effective resistance between any pair of vertices with respect to a value λ ≥ 0 and a weight ω on the vertex set. This allows us to consider a generalization of the Kirchhoff Index of a finite ...
  • Linear and Nonlinear Bullets of the Bogoliubov-de Gennes Excitations 

    Kumar, Shubham; Perego, A.M.; Staliunas, Kestutis (2017-01-27)
    Article
    Open Access
    We report on the focalization of Bogoliubov–de Gennes excitations of the nonlinear Schrödinger equation in the defocusing regime (Gross-Pitaevskii equation for repulsive Bose-Einstein condensates) with a spatially modulated ...
  • Propagation of collective modes in non-overlapping dipolar Bose-Einstein condensates 

    Gallemí Camacho, Alberto (Universitat Politècnica de Catalunya, 2013-07-19)
    Master thesis
    Open Access
    [ANGLÈS] We have studied the propagation of different collective modes of excitation (dipolar, monopolar and quadrupolar) in double and triple-well configurations in dipolar Bose-Einstein Condensates, due to the long-range ...
  • Shadowing of non-transversal heteroclinic chains 

    Delshams Valdés, Amadeu; Simon, Adriá; Zgliczynski, Piotr (2017-12-01)
    Article
    Restricted access - publisher's policy
    © 2017 Elsevier Inc. We present a new result about the shadowing of non-transversal chain of heteroclinic connections based on the idea of dropping dimensions. We illustrate this new mechanism with several examples. As an ...
  • Software refactoring: solving the time-dependent Schrodinger equation via fast Fourier transforms and parallel programming 

    Khwaldeh, Ali; Tahat, Amani; Martí Rabassa, Jordi (2012-10-30)
    Article
    Restricted access - publisher's policy
    In this study a multiprocessor C++ message passing interface implementation of a new bit-reversal algorithm to numerically solve the time dependent Schrodinger equation using a spectral method based on Fourier transform ...
  • Symmetries of the Free Schrodinger Equation in the Non-Commutative Plane 

    Batlle Arnau, Carles; Gomis, Jaoquim; Kamimura, kiyoshi (2014-01-01)
    Article
    Open Access
    We study all the symmetries of the free Schrodinger equation in the non-commutative plane. These symmetry transformations form an infinite-dimensional Weyl algebra that appears naturally from a two-dimensional Heisenberg ...