5 papers
A limsup fast dynamo on
Massimo Sorella, David Villringer
We construct a time-dependent, incompressible, and uniformly-in-time Lipschitz continuous velocity field on that produces exponential growth of the magnetic energy a…
Nonlinear instability for the 3D MHD equations around the Taylor-Couette flow
Víctor Navarro-Fernández, David Villringer
We study the 3D magnetohydrodynamics (MHD) equations in an annular cylinder, perturbed around the explicit steady state given by the 3D Taylor-Couette velocity field and zero magne…
Spectral instability in the smooth Ponomarenko dynamo
Víctor Navarro-Fernández, David Villringer
We consider the kinematic dynamo equations for a passive vector in describing the evolution of a magnetic f…
A Stochastic RAGE Theorem and Enhanced Dissipation for Transport Noise
Michele Coti Zelati, Martin Hairer, David Villringer
We prove a stochastic version of the classical RAGE theorem that applies to the two-point motion generated by noisy transport equations. As a consequence, we identify a necessary a…
Alpha-unstable flows and the fast dynamo problem
Michele Coti Zelati, Massimo Sorella, David Villringer
We construct a time-independent, incompressible, and Lipschitz-continuous velocity field in that generates a fast kinematic dynamo - an instability characterized by…