The time-average and CRIM equations Time-average equation EM - CRIM equation n layers of thickness h i and velocity v i
The Kramers-Kronig relations EM Electric susceptibility J = J 1 + i J 2 : Creep function
The reciprocity principle
Babinet’s principle EM: Babinet's principle for thin conducting complementary screens implies that the sum, beyond the screen plane, of the electric and the magnetic fields equals the incident (unscreened) electric field. In elastodynamics, the principle holds for the same field (particle velocity or stress), but for complementary screens satisfying different types of boundary conditions, i.e, if the original screen is weak (stress- free condition), the complementary screen must be rigid. On the other hand, if the original screen is rigid, the complementary screen must be weak.