We consider simultaneous solutions of operator Sylvester equations (1 ≤ i ≤ k), where and are commuting k-tuples of bounded linear operators on Banach spaces and ℱ, respectively, and is a (compatible) k-tuple of bounded linear operators from ℱ to , and prove that if the joint Taylor spectra of and do not intersect, then this system of Sylvester equations has a unique simultaneous solution.
Existence and uniqueness conditions for solving singular initial and two-point boundary value problems for discrete generalized Lyapunov matrix equations and explicit expressions of solutions are given.
*Research partially supported by INTAS grant 97-1644.Consider the Deligne-Simpson problem: give necessary and sufficient conditions for the choice of the conjugacy classes Cj ⊂ GL(n,C) (resp. cj ⊂ gl(n,C)) so that there exist irreducible (p+1)-tuples of matrices Mj ∈ Cj (resp. Aj ∈ cj) satisfying the equality M1 . . .Mp+1 = I (resp. A1+. . .+Ap+1 = 0). The matrices Mj and Aj are interpreted as monodromy operators and as matrices-residua of fuchsian systems on Riemann’s sphere. We give new examples...
We study in this paper Algebraic Riccati Equations associated with single-input single-output linear time-invariant systems bounded in -norm. Our study is focused in the characterization of families of Algebraic Riccati Equations in terms of strictly positive real (of zero relative degree) substitutions applied to the associated -norm bounded system, each substitution characterizing then a particular member of the family. We also consider here Algebraic Riccati Equations associated with systems...