Eigenvalue clusters of the Landau Hamiltonian in the exterior of a compact domain.
We describe a simple linear algebra idea which has been used in different branches of mathematics such as bifurcation theory, partial differential equations and numerical analysis. Under the name of the Schur complement method it is one of the standard tools of applied linear algebra. In PDE and spectral analysis it is sometimes called the Grushin problem method, and here we concentrate on its uses in the study of infinite dimensional problems, coming from partial differential operators of mathematical...
Analytic continuation and domains of holomorphy for solution to the complex Laplace and Dirac equations in are studied. First, geometric description of envelopes of holomorphy over domains in is given. In more general case, solutions can be continued by integral formulas using values on a real dimensional cycle in . Sufficient conditions for this being possible are formulated.
L’objet de cet exposé est de montrer comment l’évolution de Schrödinger pour le problème à corps quantique est approchée, lorsque tend vers l’infini, dans un régime convenable, par une évolution non-linéaire en dimension trois d’espace. On traitera le cas des bosons, qui conduit à l’équation de Schrödinger-Poisson, et celui des fermions, qui débouche sur le système de Hartree-Fock.
We study an Helium atom (composed of one nucleus and two electrons) submitted to a general time dependent electric field, modeled by the Hartree-Fock equation, whose solution is the wave function of the electrons, coupled with the classical Newtonian dynamics, for the position of the nucleus. We prove a result of existence and regularity for the Cauchy problem, where the main ingredients are a preliminary study of the regularity in a nonlinear Schrödinger equation with semi-group techniques and...