Superposition formulas for pseudounitary matrix Riccati equations

The purpose of this article is to derive a superposition formula for the pseudounitary matrix Riccati equation of dimension N greater than or equal to 2. The superposition formula will be written in closed form in terms of five particular solutions satisfying certain well-specified conditions defining a fundamental set. Examples will be studied in order to show how the superposition formula works and how it can be used in numerical calculations. (C) 1996 American Institute of Physics.