Weak spectral mapping theorems for C_0-groups associated to transport equations in slab geometry

We show in this paper that the C0-groups governing neutron transport equations with reflecting boundary conditions in slab geometry satisfy a weak spectral mapping theorem in any L^p spaces 1 \leq p < \infty. The main part of this paper is dealing with collisionless transport C0-group while the full transport C0-group is dealt with by stability arguments