
In this book we study orthogonal polynomials and their generalizations in spaces with weighted inner products. The impetus for our research was a deep theorem due to M.G. Krein along with subsequent results of Krein and H. Langer. Together with our colleagues, we have worked...

1 Orthogonal Polynomials and Krein's Theorem.- 2 Reformulations of Krein's Theorem.- 3 Inner Products on Modules and Orthogonalization with Invertible Squares.- 4 Orthogonal Matrix Polynomials.- 5 Special Class of Block Toeplitz Matrices.- 6 Orthogonal Operator-Valued Polynomials:...