Exponential mixing with random cellular flows via hypocoercivity
Talk by Dr. Victor Navarro-Fernández
Speaker invited by: Prof. Dr. Klaus Widmayer
Date: 06.03.25 Time: 16.15 - 18.00 Room: Y27H46
We study a passive scalar equation on a two-dimensional periodic box, where the advecting velocity field is given by a cellular flow with a randomly moving center. We prove that the passive scalar undergoes mixing at an exponential rate, independent of any underlying diffusivity. Furthermore, we show that the velocity field enhances dissipation, and we establish sharp decay rates that, for large times, are deterministic and remain uniform in the diffusivity constant. Our approach is purely Eulerian and relies on a suitable modification of Villani's hypocoercivity method. This is a joint project with C. Seis (Universität Münster).