Dmitriev [Microwave Opt Technol Lett 27 (2000) 201-203] recently contended that the so-called Post constraint holds only for reciprocal and spatiotemporally local media. Having provided general proofs earlier, we point out that the Post constraint thus is not restricted, but applies to all linear media-whether spatiotemporally local or nonlocal, spatiotemporally homogeneous or nonhomogeneous, and reciprocal or nonreciprocal.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering