Neutrino signatures of supernova turbulence

Convection that develops behind the shock front during the first second of a core-collapse supernova explosion is believed to play a crucial role in the explosion mechanism. We demonstrate that the resulting turbulent density fluctuations may be directly observable in the neutrino signal starting at t>~ 3-4 s after the onset of the explosion. The effect comes from the modulation of the MSW flavor transformations by the turbulent density fluctuations. We derive a simple and general criterion for neutrino flavor depolarization in a Kolmogorov-type turbulence and apply it to the turbulence seen in modern numerical simulations. The turbulence casts a "shadow", by making other features, such as the shock front, unobservable in the density range covered by the turbulence.