Multiblock Problems for Almost Periodic Matrix Functions of Several Variables

摘要

In this paper we solve positive and contractive multiblock problems in theWiener algebra of almost periodic functions of several variables. We thusgeneralize the classical four block problem that appears inrobust control in many ways. The necessary and sufficient conditions are interms ofappropriate Toeplitz (positive case) and Hankel operators (contractive case) onBesikovitch space. In addition, a model matching interpretation is given,and some more generalpatterns are treated aswell.