Lattice properties of sets of semidefinite solutions of continuous-time algebraic Riccati equations
From the Introduction: ``The set of negative-semidefinite solutions of the algebraic Riccati equation \(A^* X+ XA+ XBB^* X- C^* C= 0\) is studied under the hypothesis that \((A, B)\) is stabilizable modulo the undetectable subspace''.
scientific article; zbMATH DE number 758482