Abstract. A generalization of a result of L. A. Simakova on $j_{pq}$-contractive matrix valued functions is given in this note. L. A. Simakova was able to show that a matrix valued function is $j_{pq}$-contractive matrix valued if certain linear fractional transformations defined by such a matrix function maps the class of Schur functions into the class of Schur functions. We consider an indefinite analogue of these matrix functions where the corresponding matrix kernel has $\kappa $ negative squares. These indefinite analogues can then be characterized by the fact that the mentioned linear fractional transformations defined by such a matrix function maps the class of Schur functions into a certain class of indefinite Schur functions.

AMS Subject Classification (1991): 30D50, 47A56, 47A57, 47B50

Keyword(s): J, -contractive matrix functions, linear fractional transformation, Pontryagin space, indefinite kernel

Received February 12, 2001, and in revised form May 9, 2001. (Registered under 2846/2009.)