Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1900102 | Wave Motion | 2015 | 8 Pages |
•Maxwell’s equations with electric and magnetic fields mutually parallel are studied.•General plane- and spherical-wave solutions are found.•Other wave solutions cannot be as general as the plane- or spherical-wave solution.
General plane-wave and spherical-wave solutions are found for Maxwell’s equations with electric and magnetic fields parallel to each other everywhere in a uniform isotropic sourceless medium. For deriving them, Beltrami’s and Chang–Carovillano–Low’s results about a Beltrami flow (or a force-free field) with a non-constant proportionality factor are applied to Uehara–Kawai–Shimoda’s equations. It is proved that other wave solutions, such as a cylindrical-wave solution, cannot be as general as the plane-wave or spherical-wave solution.