Now showing items 1-20 of 25

  • Analysis of a viscoelastic spring-mass model 

    Pellicer Sabadí, Marta; Solà-Morales Rubió, Joan de (2003)
    Article
    Open Access
    In this paper we consider a linear wave equation with strong damping and dynamical boundary conditions as an alternative model for the classical spring-mass-damper ODE. Our purpose is to compare analytically these two ...
  • An invertible contraction that is not C<sup>1</sup>-linearizable 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2004)
    Article
    Open Access
    We present an example of a smooth invertible contraction in aninfinite-dimensional Hilbert space that is not locally ${\mathcalC}^{1}$-linearizable near its fixed point.
  • A Note on the Dynamics of Piecewise-Autonomous Bistable Parabolic Equations 

    Fiedler, Bernold; Rocha, Carlos; Salazar, Domingo; Solà-Morales Rubió, Joan de (2000)
    Article
    Open Access
  • A note on the relationship between spectral radius and norms of bounded linear operators 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2009)
    Article
    Open Access
    Let X be a Banach space and L ( X ) be the Banach algebra of bounded operators on X . In this note we prove that if we have a compact subset K of a commutative sub-algebra of L ( X ), and given " > 0, then ...
  • A result on class-C1 linearization of contractions in infinite dimensions 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2002)
    Article
    Open Access
  • A singular initial value problem to construct density-equalizing maps 

    Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2011-05)
    External research report
    Open Access
    The diffusion-based algorithm to produce density-equalizing maps interprets diffusion as an advection process. This algorithm uses the dynamics of a flow that is defined by an initial value problem that turns out to be ...
  • A singular initial value problem to construct density-equalizing maps 

    Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2011-12)
    Article
    Restricted access - publisher's policy
    The diffusion-based algorithm to produce density-equalizing maps interprets diffusion as an advection process. This algorithm uses the dynamics of a flow that is defined by an initial value problem that turns out to be ...
  • Bounded solutions of some nonlinear elliptic equations in cylindrical domains 

    Calsina Ballesta, Ángel; Solà-Morales Rubió, Joan de; València Guitart, Marta (1997)
    Article
    Open Access
    The existence of a (unique) solution of the second order semilinear elliptic equation $$ \sum^{n}_{i,j=0}a_{ij}(x)u_{x_{i}x_{j}}+f(\nabla u,u,x)=0 $$ with $x=(x_{0},x_{1},\dots, x_{n})\in (s_{0},\infty )\times \Omega '$, ...
  • Convergence to steady-state and boundary layer profiles in a linear chromatography system 

    Menacho, Joaquín; Solà-Morales Rubió, Joan de (2015-01-01)
    Article
    Restricted access - publisher's policy
    We study the hyperbolic system of equations of the so-called linear transport model in a true moving bed chromatography device with four ports. By using methods based on a suitable energy functional we show that all solutions ...
  • Diffeomorphisms with Given Jacobians involving the Heat Equation 

    Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2000-12)
    Article
    Open Access
  • Differentiability with respect to parameters in global smooth linearization 

    Rodrigues, Hildebrando M.; Solà-Morales Rubió, Joan de (2017-03-15)
    Article
    Restricted access - publisher's policy
    Let XX be a Banach space and T¿:X¿XT¿:X¿X a family of invertible contractions, T¿=L¿+f¿T¿=L¿+f¿, where L¿L¿ is linear and f¿f¿ is nonlinear with f¿(0)=0f¿(0)=0. We give conditions for the existence of a family of global ...
  • Equacions diferencials i models 

    Solà-Morales Rubió, Joan de (2014-01-30)
    Other
    Open Access
    En tot cas, jo voldria que aquesta conferència fos això que he dit: una breu lliçó sobre la importància de les equacions diferencials. Parlaré d'elles des de el punt de vista del models, és a dir, dels fenòmens que modelitzeu. ...
  • Instability and bifurcation in a trend depending price formation model 

    González Nogueras, María del Mar; Gualdani, Maria Pia; Solà-Morales Rubió, Joan de (2016-08)
    Article
    Open Access
    A well-known model due to J.-M. Lasry and P.L. Lions that presents the evolution of prices in a market as the evolution of a free boundary in a diffusion equation is modified in order to show instabilities for some values ...
  • Invertible contractions and asymptotically stable ODE´s that are not C<sup>1</sup>-linearizable 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2005)
    Article
    Open Access
    We present an example of a contraction di®eomorphism in in¯nite dimensions that is not C1-linearizable, and we construct a regular ordinary di®erential equation in a Hilbert space whose time-one map is that di®eomorphism. ...
  • Known results and open problems on C1 linearization in Banach spaces 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2012)
    Article
    Open Access
    The purpose of this paper is to review the results obtained by the authors on linearization of dynamical systems in infinite dimen- sional Banach spaces, especially in the C 1 case, and also to present some open ...
  • Layer solutions in a halfspace for boundary reactions 

    Cabré Vilagut, Xavier; Solà-Morales Rubió, Joan de (2005)
    Article
    Open Access
  • Les equacions d'Euler dels fluids no viscosos 

    Solà-Morales Rubió, Joan de (2007-02-14)
    Audiovisual
    Open Access
    (...) En aquesta conferència intentarem exposar alguns dels problemes matemàtics que aquestes equacions han generat al llarg dels seus dos-cents cinquanta anys d’existència, deixant una mica de banda la investigació ...
  • Linearization of class C1 for contractions on Banach Spaces 

    Munhoz Rodrigues, Hildebrando; Solà-Morales Rubió, Joan de (2003)
    External research report
    Open Access
    In this work we prove a C1-linearization result for contraction diffeomorphisms, near a fixed point, valid in infinite dimensional Banach spaces. As an intermediate step, we prove a specific result of existence of invariant ...
  • Nonreal eigenvalues for second order differential operators on networks with circuits 

    Lubary Martínez, José Antonio; Solà-Morales Rubió, Joan de (2001)
    Article
    Open Access
  • On maps with given jacobians involving the heat equation 

    Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2000)
    Article
    Open Access
    In this paper we presennt and analyze two new algorithms to construct a smooth diffeomorphism of a domain with prescribed jacobian function. The first one is free from any restriction on the boundary, while the second ...