2023-11-15 15:00  P7F Seminar Room

[Journal Club] Linear instability analysis of collective flavor oscillation under turbulent media fluctuation

Mr. Jordan Chen

The collective flavor oscillations of neutrinos may play important roles in supernova dynamics and affect the expected neutrino signals from nearby supernova events. In this work, we systematically investigate the impact of the presence of matter density fluctuations on the occurrence of collective oscillations. An earlier work (arXiv:2007.13655) suggests that the matter fluctuation due to turbulence can couple the neutrino flavor evolution of different Fourier modes in the linearized regime. This novel effect of coupling can potentially lead to the leakage of flavor instability from the unstable higher Fourier modes to the lower ones that are otherwise stable, and affects the onset condition of flavor oscillations. Through detailed analysis, we confirm the presence of this coupling effect. However, our results also indicate that the instability growth rate of a turbulent-coupled system is nearly identical to the non-turbulent ones. Differences in the evolution of lower modes only emerge at a later time when the system has entered the non-linear regime. Thus, it requires a full calculation of the non-linear regime to explore further whether this effect can bring any changes to the system.