The nonclassical diffusion approximation to the nonclassical linear Boltzmann equation

We show that, by correctly selecting the probability distribution function p(s) for a particle's distance-to-collision, the nonclassical diffusion equation can be represented exactly by the nonclassical linear Boltzmann equation for an infinite homogeneous medium. This choice of p(s) preserves the true mean-squared free path of the system, which sheds new light on the results obtained in previous work.