# Entanglement and collective flavor oscillations in a dense neutrino gas

## TL;DR

This paper explores how quantum entanglement influences collective neutrino oscillations in dense gases, highlighting the limitations of mean-field approximations and employing many-body physics tools.

## Contribution

It introduces the use of entanglement measures to analyze neutrino oscillations, advancing understanding beyond traditional mean-field models.

## Key findings

- Entanglement significantly affects neutrino oscillation dynamics.
- Mean-field approximation can overlook important quantum correlations.
- Comparisons show differences between many-body and mean-field evolution.

## Abstract

We investigate the importance of going beyond the mean-field approximation in the dynamics of collective neutrino oscillations. To expand our understanding of the coherent neutrino oscillation problem, we apply concepts from many-body physics and quantum information theory. Specifically, we use measures of nontrivial correlations (otherwise known as "entanglement") between the constituent neutrinos of the many-body system, such as the entanglement entropy and the Bloch vector of the reduced density matrix. The relevance of going beyond the mean field is demonstrated by comparisons between the evolution of the neutrino state in the many-body picture vs the mean-field limit, for different initial conditions.