Mathematics Colloquia and Seminars
Weak solutions of ideal MHD which do not conserve magnetic helicityPDE and Applied Math Seminar
|Speaker:||Vlad Vicol, Courant, NYU|
|Start time:||Thu, Oct 24 2019, 4:30PM|
We construct weak solutions to the ideal magneto-hydrodynamic (MHD) equations which have finite total energy, and whose magnetic helicity is not a constant function of time. In view of Taylor’s conjecture, this proves that there exist finite energy weak solutions to ideal MHD which cannot be attained in the infinite conductivity and zero viscosity limit. Our proof is based on a Nash-type convex integration scheme with intermittent building blocks adapted to the geometry of the MHD system. This is joint work with R. Beekie and T. Buckmaster.