Some new properties in Fredholm theory, Schechter essential spectrum, and application to transport theory.
Some results concerning the Poisson-Boltzmann equation
Spectral analysis of perturbed multiplication operators occurring in polymerization chemistry
Spectral Galerkin approximation of Fokker-Planck equations with unbounded drift
This paper is concerned with the analysis and implementation of spectral Galerkin methods for a class of Fokker-Planck equations that arises from the kinetic theory of dilute polymers. A relevant feature of the class of equations under consideration from the viewpoint of mathematical analysis and numerical approximation is the presence of an unbounded drift coefficient, involving a smooth convex potential that is equal to along the boundary of the computational domain . Using a symmetrization...
Spectral Galerkin approximation of Fokker-Planck equations with unbounded drift
This paper is concerned with the analysis and implementation of spectral Galerkin methods for a class of Fokker-Planck equations that arises from the kinetic theory of dilute polymers. A relevant feature of the class of equations under consideration from the viewpoint of mathematical analysis and numerical approximation is the presence of an unbounded drift coefficient, involving a smooth convex potential U that is equal to +∞ along the boundary ∂D of the computational domain D. Using a symmetrization...
Spectral statistics for random Schrödinger operators in the localized regime
We study various statistics related to the eigenvalues and eigenfunctions of random Hamiltonians in the localized regime. Consider a random Hamiltonian at an energy in the localized phase. Assume the density of states function is not too flat near . Restrict it to some large cube . Consider now , a small energy interval centered at that asymptotically contains infintely many eigenvalues when the volume of the cube grows to infinity. We prove that, with probability one in the large volume...
Spikes in two coupled nonlinear Schrödinger equations
Splitting d'opérateur pour l'équation de transport neutronique en géométrie bidimensionnelle plane
Splitting d'opérateur pour l'équation de transport neutronique en géométrie bidimensionnelle plane
The aim of this work is to introduce and to analyze new algorithms for solving the transport neutronique equation in 2D geometry. These algorithms present the duplicate favors to be, on the one hand faster than some classic algorithms and easily to be implemented and naturally deviced for parallelisation on the other hand. They are based on a splitting of the collision operator holding amount of caracteristics of the transport operator. Some numerical results are given at the end of this work. ...
Stability of hydrodynamic model for semiconductor
In this paper we study the stability of transonic strong shock solutions of the steady state one-dimensional unipolar hydrodynamic model for semiconductors in the isentropic case. The approach is based on the construction of a pseudo-local symmetrizer and on the paradifferential calculus with parameters, which combines the work of Bony-Meyer and the introduction of a large parameter.
Stability of solitary waves for a system of nonlinear Schrödinger equations with three wave interaction
Stable defects of minimizers of constrained variational principles
Stationary states of a gas in a radiation field from a kinetic point of view
Stationary voltage current characteristics of a plasma
Statiscal polymer method: Modeling of macromolecules and aggregates with branching and crosslinking formed in random processes.
Steady tearing mode instabilities with a resistivity depending on a flux function
Steady tearing mode instabilities with a resistivity depending on a flux function
We consider plasma tearing mode instabilities when the resistivity depends on a flux function (ψ), for the plane slab model. This problem, represented by the MHD equations, is studied as a bifurcation problem. For so doing, it is written in the form (I(.)-T(S,.)) = 0, where T(S,.) is a compact operator in a suitable space and S is the bifurcation parameter. In this work, the resistivity is not assumed to be a given quantity (as usually done in previous papers, see [1,2,5,7,8,9,10], but it depends...
Stimuli-Responsive Polymers in Nanotechnology: Deposition and Possible Effect on Drug Release
Stimuli-responsive polymers result in on-demand regulation of properties and functioning of various nanoscale systems. In particular, they allow stimuli-responsive control of flow rates through membranes and nanofluidic devices with submicron channel sizes. They also allow regulation of drug release from nanoparticles and nanofibers in response to temperature or pH variation in the surrounding medium. In the present work two relevant mathematical models are introduced to address precipitation-driven...
Strong diamagnetism for general domains and application
We consider the Neumann Laplacian with constant magnetic field on a regular domain in . Let be the strength of the magnetic field and let be the first eigenvalue of this Laplacian. It is proved that is monotone increasing for large . Together with previous results of the authors, this implies the coincidence of all the “third” critical fields for strongly type 2 superconductors.
Strong disorder in semidirected random polymers
We consider a random walk in a random potential, which models a situation of a random polymer and we study the annealed and quenched costs to perform long crossings from a point to a hyperplane. These costs are measured by the so called Lyapounov norms. We identify situations where the point-to-hyperplane annealed and quenched Lyapounov norms are different. We also prove that in these cases the polymer path exhibits localization.