Temporal Instability Enables Neutrino Flavor Conversions Deep Inside Supernovae

TL;DR

This paper demonstrates that neutrino flavor conversions inside supernovae can occur due to a novel instability caused by temporal fluctuations, even in dense matter where stationary models predict stability, impacting supernova physics.

Contribution

It introduces a new mechanism where temporal instability enables flavor conversions deep inside supernovae, challenging previous stationary stability assumptions.

Findings

Neutrino gases can develop non-stationary pulsating flavor components.

Flavor conversion instabilities can occur at high densities due to this mechanism.

Potential impacts on supernova explosion dynamics and neutrino detection.

Abstract

We show that a self-interacting neutrino gas can spontaneously acquire a non-stationary pulsating component in its flavor content, with a frequency that can exactly cancel the "multi-angle" refractive effects of dense matter. This can then enable homogeneous and inhomogeneous flavor conversion instabilities to exist even at large neutrino and matter densities, where the system would have been stable if the evolution were strictly stationary. Large flavor conversions, especially close to a supernova core, are possible via this novel mechanism. This may have important consequences for the explosion dynamics, nucleosynthesis, as well as for neutrino observations of supernovae.