Dynamo effect in mirror-symmetric turbulence in the Kraichnan direct-interaction approximation

P. H. Roberts

Abstract
One of the basic methods of modern turbulence theory - the Kraichnan direct-interaction approximation - is used to show that the dispersion relation governing magnetic field growth in a conducting fluid in a uniform, statistically steady, mirror-symmetric flow is identical to that governing the temperature (for equal magnetic and thermal diffusivities). It is concluded that dynamo action cannot occur in such a flow, at least in the direct-interaction approximation.