Multidimensional causality and passivity of linear and nonlinear systems arising from physics
We start with the general notions of causality, passivity, losslessness and related concepts for a class of multidimensional systems, in particular with multidimensional causality and passivity, arising from physical considerations. While such definitions are nowhere restricted to linear systems we show that when applied to linear systems with constant parameters (coefficients) they boil down to standard notions of passivity described by positive real functions and matrices, or equivalently, by bounded real functions and matrices in several complex variables.
multidimensional causality and passivity physical causality physical passivity linear and nonlinear multidimensional systems linear constant parameter systems