Kinetic theory seminar

We are pleased to announce the fourth edition of the "Kinetic Theory Seminar.” 

This seminar series brings together researchers interested in kinetic theory from the Zurich and Basel area. There will be one event per semester, alternating locations between the ETH Zurich and the University of Basel.

The next edition will celebrate the achievements of women in the field in the framework of the May12 initiative:

https://may12.womeninmaths.org/why  

 

Date: Friday, 26th May 2023

Time: 2:15 p.m. – 5:00 p.m.

2.15-3.15 First talk and discussions.

3.15-4.00 Coffee Break

4.00-5.00 Second talk and discussions.

                   

Room: ETH Zurich, HG G 19.2

Speakers: 

 

 

Prof. Giada Basile (Sapienza University of Rome)

Title: Asymptotic probability of energy increasing paths for the Kac's walk.

 

Abstract:

I will present some recent results on large deviations for   binary collision stochastic models. The paradigmatic model is the Kac’s walk, described, in the kinetic limit, by the homogeneous Boltzmann equation. I will discuss the large deviation principle and I will exhibit some atypical paths that violate energy conservation. In particular, I will compute the asymptotic probability of energy increasing paths. 
Joint work with L. Bertini, D. Benedetto and E. Caglioti.

 

 

Dr. Megan Griffin-Pickering (UCL)

Title:  The Vlasov-Poisson system for ions: recent developments on the quasi-neutral limit

 

Abstract:

Vlasov-Poisson systems are a well-known class of kinetic models for plasma. The precise structure of the model differs according to which species of particle (electrons or ions) it describes, with the `classical’ version of the system describing electrons. The model for ions, however, has been studied only more recently, owing to an additional exponential nonlinearity in the equation for the electrostatic potential that creates several mathematical  difficulties not encountered in the electron case.

 

The Debye length is a characteristic length scale of a plasma describing the scale of electrostatic interaction. In real plasmas this length is typically very small, and in physics applications frequently assumed to be very close to zero. This motivates the study of the limiting behaviour of Vlasov-Poisson type systems as the Debye length tends to zero relative to the observation scale—known as the ‘quasi-neutral’ limit. In the case of the ionic model, the formal limit is the kinetic isothermal Euler system; however, this limit is highly non-trivial to justify rigorously and known to be false in some cases without very strong regularity conditions and/or structural conditions.

 

I will discuss recent developments in the theory of the quasi-neutral limit for the ionic Vlasov-Poisson system—in particular, recent results for a certain class of rough (L^\infty) data that may be expressed as perturbations of an analytic function, small in the sense of Monge-Kantorovich-Wasserstein distances. The smallness of the perturbation that we require is much less restrictive than in the previously known results.

Based on joint works with Mikaela Iacobelli (ETH Zurich).