Sayed, Ali H.Hassibi, BabakKailath, Thomas2017-12-192017-12-192017-12-19199510.1109/ACC.1995.532764https://infoscience.epfl.ch/handle/20.500.14299/143158We study the relation between the solutions of two minimization problems with indebite quadratic forms. We show that a complete link between both solutions can be established by invoking a fundamental set of inertia conditions. While these inertia conditions are automatically satisfied in a standard Hilbert space setting, they nevertheless turn out to mark the differences between the two optimizationproblems in indefinite metric spaces. They also include, as special cases, the well-known conditions for the existence of Hoo-filters and controllers.text::conference output::conference proceedings::conference paper