Transport Equation in an Accelerated Material, Legendre Moments, and a Diffusion Approximation

The Boltzmann equation in an accelerated medium is described and the Legendre moments of the equation, formulated in velocities relative to that medium, are obtained for one-dimensional plane and spherical geometries. The accelerated medium effectively introduces additional velocity-dependent terms into the usual moment equations. The P_n scheme is suggested for the coupled channel equations and a low-order diffusion approximation accounting for the acceleration of the medium proposed.