Renormalized viscosity, renormalized resistivity, and various energy ???uxes are calculated for helical magnetohydrodynamics using perturbative ???eld theory. The calculation is of ???rst-order in perturbation. Kinetic and magnetic helicities do not affect the renormalized parameters, but they induce an inverse cascade of magnetic energy. The sources for the large-scale magnetic ???eld have been shown to be (1) energy ???ux from large-scale velocity ???eld to large-scale magnetic ???eld arising due to non-helical interactions and (2) inverse energy ???ux of magnetic energy caused by helical interactions. Based on our ???ux results, a primitive model for galactic dynamo has been constructed. Our calculations yield dynamo time-scale for a typical galaxy to be of the order of 108 years. Our ???eld-theoretic calculations also reveal that the ???ux of magnetic helicity is backward, consistent with the earlier observations based on absolute equilibrium theory.
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