We show that the field of a charge at rest can always be considered as a superposition of evanescent waves of zero frequency. By proposing a two-dimensional Fourier expansion (instead of the three-dimensional one imposed by Landau and Lifshitz), we obtain a development of the Coulomb field in plane evanescent waves of zero frequency. This development is not valid in an arbitrary plane that contains the charge. By proposing a one-dimensional Fourier expansion we obtain a development in cylindrical evanescent waves of zero frequency. This last development is not valid in an arbitrary axis that contains the charge. These expansions enable us to analyze electrostatic boundary-value problems in a novel way.
© 1980 Optical Society of AmericaFull Article | PDF Article
OSA Recommended Articles
R. Asby and E. Wolf
J. Opt. Soc. Am. 61(1) 52-59 (1971)
Emil Wolf and John T. Foley
Opt. Lett. 23(1) 16-18 (1998)
J. Opt. Soc. Am. B 16(5) 835-847 (1999)