Dynamic fast flavor oscillation waves in dense neutrino gases

TL;DR

This paper demonstrates that fast flavor oscillation waves can spontaneously develop in a 1D dense neutrino gas with crossing angular distributions, remaining coherent and transporting lepton number, which may impact supernova evolution.

Contribution

It reveals the spontaneous emergence and coherence of fast flavor oscillation waves in a 1D neutrino gas, contrasting with previous 2D models.

Findings

Fast flavor oscillation waves develop spontaneously in 1D neutrino gases.

These waves remain coherent in position and momentum spaces.

Lepton number is redistributed and transported by the waves.

Abstract

The flavor transformation in a dense neutrino gas can have a significant impact on the physical and chemical evolution of its surroundings. In this work we demonstrate that a dynamic, fast flavor oscillation wave can develop spontaneously in a one-dimensional (1D) neutrino gas when the angular distributions of the electron neutrino and antineutrino cross each other. Unlike the 2D stationary models which are plagued with small-scale flavor structures, the fast flavor oscillation waves remain coherent in the dynamic 1D model in both the position and momentum spaces of the neutrino. The electron lepton number is redistributed and transported in space as the flavor oscillation wave propagates, although the total lepton number remains constant. This result may have interesting implications in the neutrino emission in and the evolution of the compact objects such as core-collapse supernovae.