Matthieu Leautaud (Orsay)
On uniform observability of gradient flows in the vanishing
Abstract: We consider a transport equation by a gradient vector field
with a small viscous perturbation. We study uniform observability
properties from a small subset in the (singular) vanishing viscosity
limit. We prove with a series of examples that in general, the minimal
time for uniform observability may be much larger than the minimal time
needed for the observability of the limit equation.
We also prove that the two minimal times coincide for positive solutions.
This is a joint work with Camille Laurent.