Growing a magnetic field in a turbulent plasma

James Beattie (University of Toronto)

April 24, 2024

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Abstract: From the terrestrial scales of the Earth’s atmosphere, to the scales of the intracluster medium, the plasma in our Universe is turbulent. Moreover, be it through astrophysical or primordial origins, our Universe is equipped with magnetic fields that play a dynamical role in the evolution of many phenomena. In this blackboard talk I will present a chronology of the different phases that a magnetic field undergoes when coupled to turbulence through the turbulent dynamo. I will start with a basic primer on fluid turbulence and the turbulent energy spectrum, before adding a seed magnetic field and growing it in the fast diffusion free and diffusion regimes. Time permitting, I will comment upon nonlinear (secular growth) phase, including the latest theories on the growth of tearing instabilities, leading to the saturated, time-independent state of the magnetic field.