{ "id": "1804.08505", "version": "v1", "published": "2018-04-23T15:27:19.000Z", "updated": "2018-04-23T15:27:19.000Z", "title": "Standard versus Bounded Real Lemma with infinite-dimensional state space II: The storage function approach", "authors": [ "J. A. Ball", "G. J. Groenewald", "S. ter Horst" ], "comment": "45 pages, to appear in Operator Theory: Advances and Applications volume", "categories": [ "math.FA" ], "abstract": "For discrete-time causal linear input/state/output systems, the Bounded Real Lemma explains (under suitable hypotheses) the contractivity of the values of the transfer function over the unit disk for such a system in terms of the existence of a positive-definite solution of a certain Linear Matrix Inequality (the Kalman-Yakubovich-Popov (KYP) inequality). Recent work has extended this result to the setting of infinite-dimensional state space and associated non-rationality of the transfer function, where at least in some cases unbounded solutions of the generalized KYP-inequality are required. This paper is the second installment in a series of papers on the Bounded Real Lemma and the KYP inequality. We adapt Willems' storage-function approach to the infinite-dimensional linear setting, and in this way reprove various results presented in the first installment, where they were obtained as applications of infinite-dimensional State-Space-Similarity theorems, rather than via explicit computation of storage functions.", "revisions": [ { "version": "v1", "updated": "2018-04-23T15:27:19.000Z" } ], "analyses": { "subjects": [ "47A63", "47A48", "93B20", "93C55", "47A56" ], "keywords": [ "bounded real lemma", "infinite-dimensional state space", "storage function approach", "discrete-time causal linear input/state/output systems" ], "note": { "typesetting": "TeX", "pages": 45, "language": "en", "license": "arXiv", "status": "editable" } } }