The corona-dynamo connection in accretion disks

The theory of mean-field dynamos in accretion disks has been discussed at length in numerous papers, dating back almost to the first theoretical papers on accretion disks. In the last decade the theory of mean-field dynamos in almost perfectly conducting fluids has been subjected to strong criticisms, based on general theoretical considerations and as well as numerical tests. Paradoxically, the numerical evidence for mean-field dynamo activity …