Stable factorization of Hankel and Hankel-like matrices

This paper gives displacement structure algorithms for the factorization positive definite and indefinite Hankel and Hankel-like matrices. The positive definite algorithm uses orthogonal symplectic transformations in place of the Sigma-orthogonal transformations used in Toeplitz algorithms. The indefinite algorithm uses a look-ahead step and is based on the observation that displacement structure algorithms for Hankel factorization have a natural and simple block generalization. Both algorithms can be applied to Hankel-like matrices of arbitrary displacement rank.