Eur. Phys. J. Special Topics 227, 1205–1219 (2018)
https://doi.org/10.1140/epjst/e2018-800085-0

Regular Article

Characteristics of in-out intermittency in delay-coupled FitzHugh–Nagumo oscillators

Theoretical Physics/Complex Systems, ICBM, University of Oldenburg, 26129 Oldenburg, Germany

^a e-mail: arindam.saha@uni-oldenburg.de

Received: 1 May 2018
Received in final form: 15 June 2018
Published online: 12 December 2018

Abstract

We analyze a pair of delay-coupled FitzHugh–Nagumo oscillators exhibiting in-out intermittency as a part of the generating mechanism of extreme events. We study in detail the characteristics of in-out intermittency and identify the invariant subsets involved – a saddle fixed point and a saddle periodic orbit – neither of which are chaotic as in the previously reported cases of in-out intermittency. Based on the analysis of a periodic attractor possessing in-out dynamics, we can characterize the approach to the invariant synchronization manifold and the spiralling out to the saddle periodic orbit with subsequent ejection from the manifold. Due to the striking similarities, this analysis of in-out dynamics also explains in-out intermittency