Correct statement of a scattering problem for quantum charged scalar particles on the Reissner-Nordstr\"{o}m black holes

We study a correct statement of the scattering problem arising for quantum charged scalar particles on the Reissner-Nordstr\"{o}m black holes when taking into account the own electric field of black hole. The elements of the corresponding S-matrix are explored in the form convenient to physical applications and for applying numerical methods. Some further possible issues are outlined.Comment: 12 pages, LaTeX with using the ijmpd1.sty file from the package of World Scientific Publishing Co., to appear in Int. J. Mod. Phys. D7 (1998

Electrons scattering in the monolayer graphene with the short-range impurities

Scattering problem for electrons in monolayer graphene with short-range perturbations of the types "local chemical potential" and "local gap" has been solved. Zero gap and non-zero gap kinds of graphene are considered. The determined S-matrix can be used for calculation of such observables as conductance and optical absorption