Speaker
Prof.
Albert-László Barabási
(Northeastern University)
Description
The ultimate proof of our understanding of natural or
technological systems is reflected in our ability to control
them. While control theory offers mathematical tools to
steer engineered and natural systems towards a desired
state, we lack a framework to control complex self-organized
systems. Here we develop analytical tools to study the
controllability of an arbitrary complex directed network,
identifying the set of driver nodes whose time-dependent
control can guide the system’s entire dynamics. We apply
these tools to several real networks, finding that the
number of driver nodes is determined mainly by the network’s
degree distribution. We show that sparse inhomogeneous
networks, which emerge in many real complex systems, are the
most difficult to control, but dense and homogeneous
networks can be controlled via a few driver nodes.
Counterintuitively, we find that in both model and real
systems the driver nodes tend to avoid the hubs.