Chiral plasma instability and inverse cascade from nonequilibrium left-handed neutrinos in core-collapse supernovae

TL;DR

This paper demonstrates that nonequilibrium left-handed neutrinos can induce a chiral electric current in supernova matter, leading to magnetic field amplification via plasma instability, potentially explaining magnetar magnetic fields and affecting supernova dynamics.

Contribution

It introduces a novel mechanism where neutrino-induced chiral currents generate magnetic fields in supernovae, based on chiral radiation transport theory.

Findings

Neutrino backreaction induces electric currents without electron chiral imbalance.

Chiral plasma instability can generate strong magnetic fields in supernovae.

Chiral effects significantly alter supernova hydrodynamics and explosion processes.

Abstract

We show that the backreaction of left-handed neutrinos out of equilibrium on the matter sector induces an electric current proportional to a magnetic field even without a chiral imbalance for electrons in core-collapse supernovae. We derive the transport coefficient of this effect based on the recently formulated chiral radiation transport theory for neutrinos. This chiral electric current generates a strong magnetic field via the so-called chiral plasma instability, which could provide a new mechanism for the strong and stable magnetic field of magnetars. We also numerically study the physical origin of the inverse cascade of the magnetic energy in the magnetohydrodynamics including this current. Our results indicate that incorporating the chiral effects of neutrinos would drastically modify the hydrodynamic evolutions of supernovae, which may also be relevant to the explosion dynamics.