Frédéric van Wijland (Université Paris Diderot, France) - Jeudi 6 mars.
Living cells are chemically driven systems that produce, on top of thermal noise, a wealth of nonequilibrium fluctuations. These fluctuations can be accessed, and quantified, by embedding a tracer inside the cell. By manipulating the tracer it is possible to subject the living medium to external perturbations, the response to which teaches us about the inner activity of the cell (time scales, power injected by the molecular motors at work). This is achieved by exploiting recently derived relations between fluctuations and response arbitrarily far from equilibrium. In order further exploit available particle tracking data, we model the dynamics of a single tracer, which allows us to gain further insight into the details of the underlying molecular motor activity.