[institut] SCL Seminar: Matthias Wolfrum, Thursday, 11th October, 14:00

[Igor Franovic]

Dear colleagues,

you are cordially invited to the SCL seminar of the Center for the Study 
of Complex Systems, which will be held on Thursday, 11th October 2018 at 
14:00 in the library reading room "Dr. Dragan Popović" of the Institute 
of Physics Belgrade. The talk entitled

                               "Excitability of the relaxation 
oscillations in the FitzHugh-Nagumo system"

will be given by Dr Matthias Wolfrum from the Weierstrass Institute for 
Applied Analysis and Stochastics (WIAS) in Berlin. The abstract of the 
talk is provided below.

The classical notion of excitability refers to an equilibrium state that 
shows under the influence of perturbations a nonlinear threshold-like 
behavior. In this talk, we extend this concept by demonstrating how 
periodic orbits can exhibit a specific form of excitable behavior where 
the nonlinear threshold-like response appears only after perturbations 
applied within a certain part of the periodic orbit, i.e the 
excitability happens to be phase-sensitive. We demonstrate this concept 
using the relaxation oscillations of the FitzHugh-Nagumo system. 
Triggering the phase-sensitive excitability by noise leads to a 
characteristic non-monotone dependence of the mean spiking rate of the 
relaxation oscillations on the noise level. In the second part of the 
talk, we consider a system of two coupled FitzHugh-Nagumo oscillators, 
where dynamical regimes with alternating spiking order, called 
leap-frogging, appear as a consequence of the phase-sensitive 
excitability feature. We analyze various types of periodic and chaotic 
leap-frogging regimes, using numerical path-following methods to 
investigate their emergence and stability, as well as to obtain the 
complex bifurcation scenario which organizes their appearance in the 
parameter space.

Best regards,
Dr Igor Franović


----
Assistant Research Professor
Scientific Computing Laboratory
Center for the Study of Complex Systems
Institute of Physics Belgrade, Serbia
Homepage: www.scl.rs/franovic
Phone: +381 11 3713 184
Fax: +381 11 3162190
E-mail: franovic at ipb.ac.rs

Institute of Physics Belgrade
Pregrevica 118, 11080 Belgrade, Serbia
http://www.ipb.ac.rs/