The Operator Valued Autoregressive Filter Problem and the Suboptimal Nehari Problem in Two Variables
arXiv:math/0412508
Abstract
Necessary and sufficient conditions are given for the solvability of the operator valued two-variable autoregressive filter problem. In addition, in the two variable suboptimal Nehari problem sufficient conditions are given for when a strictly contractive little Hankel has a strictly contractive symbol.
18 pages