The present paper is an in depth analysis of the set of conditioned invariant subspaces of a given observable pair (C,A). We do this analysis in two different ways, one based on polynomial models starting with a characterization obtained in [P.A. Fuhrmann, Linear Operators and Systems in Hilbert Space, 1981; IEEE Trans. Automat. Control AC-26 (1981) 284], the other being a state space approach....

The μ-value or structured singular value is a prominent mathematical tool to analyze and synthesize both the robustness performance of time-invariant systems. We establish new results concerning values for Hadamard product real square M-matrices. are obtained while considering set block diagonal uncertainties. targeted uncertainties two types, that is, pure scalar full-block eigenvalue perturba...