Neutrino-driven electrostatic instabilities in a magnetized plasma

Abstract

The destabilizing role of neutrino beams on the Trivelpiece-Gould modes is considered, assuming electrostatic perturbations in a magnetized plasma composed by electrons in a neutralizing ionic background, coupled to a neutrino species by means of an effective neutrino force arising from the electro-weak interaction. The magnetic field is found to significantly improve the linear instability growth rate, as calculated for Supernova type II environments. On the formal level, for wave vector parallel or perpendicular to the magnetic field the instability growth rate is found from the unmagnetized case replacing the plasma frequency by the appropriated Trivelpiece-Gould frequency. The growth rate associated with oblique propagation is also obtained

Neutrino oscillations and instabilities in degenerate relativistic astrophysical plasmas

“…It is important to note that the Chandrasekhar equation of state gives a linear dispersion for ion-acoustic waves in the absence of neutrinos, which agrees with the result from the relativistic Vlasov equation, in the long-wavelength limit [17]. In addition, magnetized plasmas can be treated by simply including the magnetic force on electrons and ions [15]. In the case of electromagnetic waves, also the full set of Maxwell equations would be necessary [13,14].…”

“…Previously, neutrino oscillations in nonrelativistic plasmas have also been analyzed in [11] and [12], taking into account the collisional damping of ion-acoustic waves. In addition, neutrino-magnetohydrodynamic modes [13,14] and neutrinomodified wave propagation in strongly magnetized plasma * fernando.haas@ufrgs.br [15] have been considered, without the inclusion of flavor oscillations, degeneracy, or relativistic effects.…”

Instabilities and propagation of neutrino magnetohydrodynamic waves in arbitrary direction

“…This happens because k • δU = 0 for the shear Alfvén wave, which eliminates the neutrino contribution in Eq. (17). Presently, the more interesting modes comes from the second bracket in Eq.…”

“…Assuming the geometry of Fig. 1, where without loss of generality the y−component of k and V A is set to zero, and from the characteristic determinant of the homogeneous system (17) for the components of δU, the result is…”

“…Therefore, the present work removes the orthogonality condition of [16], to obtain instability growth-rates of simplified and ideal NMHD for arbitrary oblique angles between wave propagation and equilibrium magnetic field. Similarly, the instability analysis of general electrostatic perturbations in magnetized electron plus neutrino plasmas in an ionic background was recently carried on [17].…”