L'Equation de Schrรถdinger quand h tend vers zero; une approche probabiliste -- Rearrangement Gaussien de fonctions -- Electrons of a solid in an external electric field -- An intrinsic approach to the evolution of quantum observables in terms of stochastic processes on phase space -- Diffusions and central limit theorems -- Random Schrรถdinger operators and the density of states -- Ergodic properties of the Lozi map -- Proprietes spectrales pour des hamiltoniens presque-periodiques -- A solvable almost periodic Schrรถdinger operator -- On the absence of breakdown of symmetry for the plane rotator model with long range unbounded random interaction -- Stratonovich solution of a quantum stochastic differential equation describing light emission and absorption -- Analytic expansion of Lyapunov exponents associated to the Schrรถdinger operator -- Reduction of non linear problems to Schrรถdinger or heat equations: Formation of kepler orbits, singular solutions for hydrodynamical equations -- Quantum mechanical low energy scattering in terms of diffusion processes