The initial value problem for the linear Boltzmann equation describing the propagation of neutrinos in a medium composed of nuclei is rigorously solved. The structure of the equation corresponds to the Lorentz model with an angle-dependent scattering cross-section. A method yielding the rigorous...

The evolution of the one-particle distribution for a homogeneous system of hard spheres is studied. The terms in the formal density expansion of the collision operator which correspond to the class of hard sphere dynamical events involving one binary collision, the influence of other particles...