Abstract
We show that KKT-type conditions are necessary and sufficient for global optimality for some quadratically constrained (possibly nonconvex) quadratic programming QCQP problems in Hilbert space. The key property is the convexity of an image-type set, called generalized image set, related to the functions appearing in the formulation of the problem. The proof of the main result relies on a generalized version of the (Jakubovich) S-Lemma in Hilbert spaces. As an application, we consider the class of QCQP problems with a special form of the quadratic terms of the constraints.
Disclosure statement
No potential conflict of interest was reported by the author(s).