On a Classical Limit of Quantum Theory and the Non-Linear Hartree Equation

Abstract

Historically, the description of Nature in theoretical physics began with an encoding of rather special, simple natural phenomena exhibiting high approximate symmetry in special, unstable mathematical structures. For example, the shape of the orbits of planets around the sun was conceived to be circular. As the ambition to describe more general classes of natural phenomena grew those special mathematical structures had to be deformed and enlarged into more general, more stable mathematical structures. Kepler discovered that the idea of elliptic orbits, with the sun in one of the foci, provides a better model for the motion of planets.