Nonlinear systems
Nonlinear systems are everywhere, from meteorology to
biology, from chemistry to quantum mechanics,... They may exhibit amazing
behaviors (e.g. strange attractors, chaotic trajectories,...) and have remained a
tremendous topic of interest for the last decades.
Synchronization
From a mathematical point of view, synchronization is
observed in networks of coupled dynamical systems. In the real world (especially
the living world), synchronization is omnipresent and occurs in various
situations. Nature exhibits a lot of interesting and amazing examples
of perfect synchronization: asian fireflies flashing together, crickets that
chirp in unison, synchronized applause of the crowd asking for an encore
after a concert, groups of women whose menstrual periods become mutually
synchronized, synchronous firings of pacemaker cells of the heart, spiking neurons in the brain, ...
Neural networks
The electrical activity of a single neuron can be
modeled in a simple way. However, in our brain, all the neurons are connected in a
complex way so that they form a broad network. The whole network is then
considered as a (nonlinear) dynamical system of large dimension. Its
global behavior (synchronization, periodic firings,...) may be theoretically studied thanks
to system theory and model reduction.