Astrophysical magnetic fields and nonlinear dynamo theory
نویسندگان
چکیده
The current understanding of astrophysical magnetic fields is reviewed with particular emphasis on nonlinear dynamo theory. Analytic and numerical results are discussed both for small scale dynamos, where helicity is unimportant, and for large scale dynamos, where kinetic helicity is crucial. Large scale dynamos produce small scale magnetic helicity as a waste product that quenches the large scale dynamo process (alpha effect). With this in mind, the microscopic theory of the alpha effect is revisited in full detail and new results for current helicity fluxes are presented.
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