COMMON ZERO STRUCTURE OF RATIONAL MATRIX FUNCTIONS

The paper is concerned with description of common zero data of two squ are size rational matrix functions. The notion of a common null pair, which encodes the data, is introduced and studied from various points of view. The main result of the paper is a characterization of the com mon null pair in terms of realization of the functions in question. Co nnections with common minimal divisors of rational matrix functions ar e elucidated. The recently developed theory of null-pole triples and S ylvester data sets is extensively used in the proofs. (C) 1996 Academi c Press, Inc.