Neutrino magnetohydrodynamic instabilities in presence of two-flavor oscillations

TL;DR

This paper investigates how neutrino flavor oscillations influence magnetohydrodynamic wave instabilities in neutrino-beam driven plasmas, revealing enhanced instability effects that could impact supernova explosion mechanisms.

Contribution

It introduces a neutrino MHD model that incorporates flavor oscillations, showing their effect on wave dispersion and instability enhancement in magnetoplasmas.

Findings

Neutrino flavor oscillations affect MHD wave dispersion.

Oscillations enhance magnetosonic wave instability.

Shear-Alfvén wave remains unaffected.

Abstract

The influence of neutrino flavor oscillations on the propagation of magnetohydrodynamic (MHD) waves and instabilities is studied in neutrino-beam driven magnetoplasmas. Using the neutrino MHD model, a general dispersion relation is derived which manifests the resonant interactions of MHD waves, not only with the neutrino beam, but also with the neutrino flavor oscillations. It is found that the latter contribute to the wave dispersion and enhance the magnitude of the instability of oblique magnetosonic waves. However, the shear-Alfv{\'e}n wave remains unaffected by the neutrino beam and neutrino flavor oscillations. Such an enhancement of the magnitude of the instability of magnetosonic waves can be significant for relatively long-wavelength perturbations in the regimes of high neutrino number density and/or strong magnetic field, giving a convincing mechanism for type-II core-collapse supernova explosion.