Kinetic and related models with applications in the natural sciences

Puzzles in the theory of magnetic turbulence

Stanislav Boldyrev

University of Wisconsin-Madison

In situ measurements of space plasma turbulence have consistently revealed intriguing deviations from the Kolmogorov-like phenomenological predictions. At large magnetohydrodynamic scales, the spectrum of magnetic fluctuations is observed to deviate from the spectrum of velocity fluctuations. At small kinetic scales, the spectrum of turbulence is different from a simple local energy cascade model as well. We will show that these problems exist already in the limit of weak (wave-dominated) magnetic turbulence, which may help to understand the underlying reasons for the puzzling properties of plasma turbulence detected in observations.