{ "id": "2009.11544", "version": "v1", "published": "2020-09-24T08:24:01.000Z", "updated": "2020-09-24T08:24:01.000Z", "title": "Koopman Resolvent: A Laplace-Domain Analysis of Nonlinear Autonomous Dynamical Systems", "authors": [ "Yoshihiko Susuki", "Alexandre Mauroy", "Igor Mezic" ], "comment": "20 pages, 2 figures", "categories": [ "math.DS", "cs.SY", "eess.SY", "math.OC" ], "abstract": "The motivation of our research is to establish a Laplace-domain theory that provides principles and methodology to analyze and synthesize systems with nonlinear dynamics. A semigroup of composition operators defined for nonlinear autonomous dynamical systems---the Koopman semigroup and its associated Koopman generator---plays a central role in this study. We introduce the resolvent of the Koopman generator, which we call the Koopman resolvent, and provide its spectral characterization for three types of nonlinear dynamics: ergodic evolution on an attractor, convergence to a stable equilibrium point, and convergence to a (quasi-)stable limit cycle. This shows that the Koopman resolvent provides the Laplace-domain representation of such nonlinear autonomous dynamics. A computational aspect of the Laplace-domain representation is also discussed with emphasis on non-stationary Koopman modes.", "revisions": [ { "version": "v1", "updated": "2020-09-24T08:24:01.000Z" } ], "analyses": { "keywords": [ "nonlinear autonomous dynamical systems", "koopman resolvent", "laplace-domain analysis", "dynamical systems-the koopman semigroup", "autonomous dynamical systems-the koopman" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }