Transformation of Small‐Signal Energy and Momentum of Waves

摘要: The transformation of the small‐signal energy and momentum a wave between two inertial reference frames as first given by Sturrock are derived using simple perturbation theory appropriate transformations length, time, current, electromagnetic fields. approach allows straightforward generalization to case relativistic linear nonrelativistic that rotate with respect each other. These rotating allow one make very general statements about frequency wavenumbers for which negative‐energy waves obtained in translating medium, as, example, an electron beam Brillouin flow.