On the Hartman paradox, electromagnetic wave tunneling, and supraluminal velocities (comment on “Tunneling of electromagnetic waves: paradoxes and prospects” by A B Shvartsburg)
Chernyshevskii Saratov State University, ul. Astrakhanskaya 83, Saratov, 410071, Russian Federation
Some paradoxes are discussed concerning the interpretation of the passage of particles and electromagnetic waves
(pulses) across potential barriers and through nonuniform media, in particular, those with frequency dispersion and therefore dissipation. It is emphasized that a rigorous nonstationary approach does not entail any supraluminal velocities for the transfer of physical substances, although supraluminal velocities are indeed possible for several kinematically defined velocities, e.g., for the group velocity.