Now showing items 1-20 of 25

• #### Analysis of a viscoelastic spring-mass model ﻿

(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 ﻿

(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.

(2000)
Article
Open Access
• #### A note on the relationship between spectral radius and norms of bounded linear operators ﻿

(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 ...

(2002)
Article
Open Access
• #### A singular initial value problem to construct density-equalizing maps ﻿

(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 ﻿

(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 ﻿

(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 ﻿

(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 ...

(2000-12)
Article
Open Access
• #### Differentiability with respect to parameters in global smooth linearization ﻿

(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 ﻿

(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 ﻿

(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 ﻿

(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 ﻿

(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 ...

(2005)
Article
Open Access
• #### Les equacions d'Euler dels fluids no viscosos ﻿

(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 ﻿

(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 ...

(2001)
Article
Open Access
• #### On maps with given jacobians involving the heat equation ﻿

(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 ...