Chandrasekhar-Kendall functions in astrophysical dynamos

TL;DR

This paper discusses the use of Chandrasekhar-Kendall functions to analyze magnetic fields in astrophysical dynamos, presenting new high-resolution simulations that reveal different cascade behaviors for right- and left-handed magnetic contributions.

Contribution

It introduces high-resolution helically forced simulations utilizing Chandrasekhar-Kendall functions to decompose magnetic fields into chiral components, revealing their distinct cascade dynamics.

Findings

Right-handed contributions exhibit forward cascade.

Left-handed contributions show inverse transfer.

Inverse transfer speed decreases with higher magnetic Reynolds number.

Abstract

Some of the contributions of Chandrasekhar to the field of magnetohydrodynamics are highlighted. Particular emphasis is placed on the Chandrasekhar-Kendall functions that allow a decomposition of a vector field into right- and left-handed contributions. Magnetic energy spectra of both contributions are shown for a new set of helically forced simulations at resolutions higher than what has been available so far. For a forcing function with positive helicity, these simulations show a forward cascade of the right-handed contributions to the magnetic field and nonlocal inverse transfer for the left-handed contributions. The speed of inverse transfer is shown to decrease with increasing value of the magnetic Reynolds number.