Jeudi 21 février 2013
Flocking is a paradigmatic example of self-organized collective behaviour, where
collective ordering emerges from the mutual interactions between individuals. In
this respect, it shares striking similarities with collective phenomena in inanimate
systems that have long been studied by the physics community. Still, biological systems
are more complicated than physical ones and it is not evident whether they
can be described by the same kind of general laws so well understood in physics.
Experimental findings often go beyond simple expectations, making this field even
more fascinating.
In this talk I will discuss our attempts to study collective animal behaviour using a
physicist’s perspective. I will show how we used concepts and methods from statistical
physics to make sense of experimental data of large flocks of birds. In particular,
I will focus on the velocity correlation functions, that well capture the balance
between consensus and independence among the large number of individuals in
the group. We measured these correlations in real flocks of starlings and found that
they exhibit a non-trivial scale-free behavior, indicating a surprisingly large degree
of coordination and collective response. I will describe how we can use these correlations
in space and time to systematically address the inverse problem, extract
from the experimental measurements information on the underlying interactions,
and build minimal (maximum entropy) dynamical models directly from the data.
RECRUTEMENT ACCES DIRECT
Le département de physique
Fête de la Science 2018 