Neutrino oscillations and instabilities in degenerate relativistic astrophysical plasmas

Abstract

We set up a proposal to extend significantly recent works on neutrino-plasma interaction, allowing the possibility of deep degenerate and relativistic electrons, which are often present in compact stars such as high-density white dwarfs. The methodology involves the covariant hydrodynamic formulation of ultradense plasmas. We propose the generalization of previous studies, on the interaction between ion-acoustic waves and resonant neutrino flavor oscillations in a mixed neutrino beam, admitting degenerate and relativistic electron populations. Destabilization of the ion acoustic wave has higher growth rates, thanks to the very high densities present in plasmas under these extreme conditions. We take into account applications to white dwarf stars in the process of collapsing, producing type II supernovas.

Neutrino magnetohydrodynamic instabilities in presence of two-flavor oscillations

“…Here, N e (v e ) denotes the number density (velocity) of electron neutrinos. For a coherent neutrino beam with an energy 0  , the continuity equations for electron and muon neutrinos (with number density N μ , velocity v μ ), respectively, are [15,29]…”

“…It is evident from figure 2 that as one approaches towards a domain of higher wave numbers, the relative influence of flavor oscillations on the instability growth rate becomes less important. However, it can be significant for both the slow and fast magnetosonic modes at some higher density regimes, provided one limits the neutrino density below a critical value, since at higher density regimes the relativistic degeneracy of electrons should come into the picture [29] which is not considered in the present model.…”