### Recent results on quasineutral limit for Vlasov-Poisson via Wasserstein stability estimates

Mathematical Physics Seminar

16th February 2018, 2:00 pm – 3:00 pm

Howard House, 4th Floor Seminar Room

The Vlasov-Poisson system is a kinetic equation that models collisionless plasma. A plasma has a characteristic scale called the Debye length, which is typically much shorter than the scale of observation. In this case the plasma is called ‘quasineutral’. This motivates studying the limit in which the ratio between the Debye length and the observation scale tends to zero. Under this scaling, the formal limit of the Vlasov-Poisson system is the Kinetic Isothermal Euler system. The Vlasov-Poisson system itself can formally be derived as the limit of a system of ODEs describing the dynamics of a system of N interacting particles, as the number of particles approaches infinity. The rigorous justification of this mean field limit remains an open problem. In this talk we present the rigorous justification of the formal limit for very small but rough perturbations of analytic initial data for the Vlasov-Poisson equation in dimension 1, 2 and 3. Also, we will discuss a recent result in which we derive the Kinetic Isothermal Euler system from a regularised particle model. Our approach uses a combined mean field and quasineutral limit.

*Organiser*: Thomas Bothner

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