04/04/2017 Seminar of Fulvio Forni

Date de publication : Mar 30, 2017 9:20:39 AM

Date: 04/04/2017, 14h00

Location: LAGEP, Bordet

Speaker: Fulvio Forni, Lecturer in Engineering University of Cambridge, UK

Title: Differential analysis of nonlinear systems: positivity, monotonicity and interconnections. ,

Abstract: Differential analysis aims at inferring global properties of nonlinear behaviours from the local analysis of the linearised dynamics. The novel notion of differential positivity extends linear positivity to the nonlinear setting: a nonlinear system is differentially positive if its linearization along trajectories leaves a cone (field) invariant. Notably, monotone systems are differentially positive. Differential positivity extends monotonicity to manifolds, replacing order relations with local orders. The property strongly restricts the asymptotic nonlinear behavior, through suitable extensions of Perron-Frobenius theory and of results on contraction of the Hilbert metric. Motivated by the importance of positivity in linear systems theory, we discuss the relevance of the property for applications and how much the property restricts the behavior of open nonlinear systems.