Avviso di seminario, Università di Trento

"Regularization by noise for transport and kinetic equations" Martedì 31 ottobre 2017

*Luogo:* Dipartimento di Matematica, via Sommarive, 14 - Povo (TN) - Aula Seminari "-1" *Ore*: 11.00

- *Relatore: *Ennio Fedrizzi (Applied Mathematical Department, ENSTA ParisTech)

*Abstract: *For some differential equations the addition of a carefully chosen, random noise term can produce a regularising effect (e.g. solutions are more regular, or restored uniqueness). I will first mention a few easy examples (ODEs) to introduce some of these regularising mechanisms, then detail two cases where we have regularisation for a PDE: the linear transport equation and a kinetic equation with force term. I will present some classical results for these two equations, related to well-posedness and regularity of solutions, that in the stochastic setting can be obtained under weaker hypothesis. These results are based on a careful analysis of the stochastic characteristics and the regularising properties of some associated parabolic/elliptic PDE.

If time allows, I will conclude by introducing a new strategy of proof based on stochastic exponentials and an associated parabolic PDE, which allows to obtain, under even weaker hypothesis, well-posedness for stochastic PDEs in a class of solutions which are only regular in mean. This will be illustrated by an application to the transport equation.

*Referente: *Stefano Bonaccorsi