An operatorial approach of the well-posedness of an algebraic Riccati equation
arXiv:2507.20171 · doi:10.1007/s00245-026-10407-1
Abstract
Finding the state feedback control in an -optimal control problem involves a challenging approach of the associated algebraic Riccati equation of the generic form . In view of this objective, we explore in this paper the existence of the solution to this algebraic Riccati equation by a direct operatorial approach in the space of Hilbert-Schmidt operators. The proofs are provided, under certain assumptions on the operators and for the cases with coercive and respectively. They develop a constructive approach, possibly indicating a method for finding the numerical solution. Next, relying on the existence of the solution to the Riccati equation, we provide then a result concerning the associated -optimal control problem. An example regarding the application of the existence proof for the solution to the Riccati equation is given for a parabolic equation with a singular potential of Hardy type.
23 pages, no figures