The turbulent chiral-magnetic cascade in the early universe

Abstract

The presence of asymmetry between fermions of opposite handedness in plasmas of relativistic particles can lead to exponential growth of a helical magnetic field via a small-scale chiral dynamo instability known as the chiral magnetic effect. Here, we show, using dimensional arguments and numerical simulations, that this process produces through the Lorentz force chiral magnetically driven turbulence. A k^{-2} magnetic energy spectrum emerges via inverse transfer over a certain range of wavenumbers k. The total chirality (magnetic helicity plus normalized chiral chemical potential) is conserved in this system. Therefore, as the helical magnetic field grows, most of the total chirality gets transferred into magnetic helicity until the chiral magnetic effect terminates. Quantitative results for height, slope, and extent of the spectrum are obtained. Consequences of this effect for cosmic magnetic fields are discussed.

7 pages, 4 figures, 1 table, published in ApJL

References in corpus (7)

• The Chiral Magnetic Effect
• Nonhelical inverse transfer of a decaying turbulent magnetic field
• Evolution of Primordial Magnetic Fields from Phase Transitions
• Classes of hydrodynamic and magnetohydrodynamic turbulent decay
• Cosmic ray current-driven turbulence and mean-field dynamo effect
• Influence of the turbulent motion on the chiral magnetic effect in the early Universe
• Parity-odd correlators of diffuse gamma rays and intergalactic magnetic fields

Cited by in corpus (5)

• Evolution of hydromagnetic turbulence from the electroweak phase transition
• Chiral hydrodynamics in strong external magnetic fields
• Relic gravitational waves from the chiral magnetic effect
• Interaction of inhomogeneous axions with magnetic fields in the early universe
• On the measurement of handedness in Fermi Large Area Telescope data