Neutrino magnetohydrodynamic instabilities in presence of two-flavor oscillations

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-Alfvén 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.

Analysis of hyperbolic magneto-hydrodynamic [HMHD] wave propagation through neutrino-coupled plasma

“…Equation (22) represents the perpendicular mode of propagation for the neutrino beam instability in the considered neutrino-coupled plasma system. When neutrino beam contribution is not included, then equation (22) reduces in the form,…”

“…This is similar to Sharma and Chhajlani [29] and Sharma et al [7] with some limiting situations. Equation (22) shows the combined effect of the considered effect and neutrino beam on the self-gravitating magnetized plasma system. If we restrict the terms of resistivity and viscosity (h and z ) in equation ( 22), then we have…”

“…From equation (22) we can see the effect of neutrino beam contribution on the considered effects(Hall current and rotation) with, other parameters in the HMHD wave propagation system. To give the neutrino beam instability condition for unstable growing mode, let us have the neutrino beam mode as kV i cos ,…”

“…By solving equation (22) with the help of the above assumption of neutrino beam mode, one can obtain the real growth rate of perturbation as…”

“…Aftab et al [21] has been investigated the ion-neutral collision effect in plasma systems and neutrino beam-driven instability, in the presence of an oblique magnetic field for magneto-sonic waves. Recently Chatterjee et al [22] have been analyzing the role of neutrino magneto hydrodynamic instabilities under the presence of two-flavor oscillations. By many researchers, in earlier published work [1,23,24] the concept of coupling of neutrino flavour oscillation is used to investigate waves produced in magnetized and unmagnetized plasma.…”