... erential forms have WARNICK, SELFRIDGE, AND ARNOLD: DIFFERENTIAL FORMS February 12, 1997 been applied to control theory by Hermann 9] and others B Di erential Forms in EM Theory The laws of electromagnetic ... Thirring, Classical Field Theory, vol II, Springer-Verlag, New York, edition, 1978 18] K F Warnick, R H Selfridge, and D V Arnold, \Electromagnetic boundary conditions using di erential forms, " IEE Proc., ... Warnick and D V Arnold, \Electromagnetic Green functions using di erential forms, " J Elect Waves Appl., vol 10, no 3, pp 427{438, 1996 20] K F Warnick and D V Arnold, \Di erential forms in electromagnetic...