论文标题
量子动力学平衡
Quantum Kinetic Equilibrium
论文作者
论文摘要
我们解决了早期宇宙中主动性中微子系统的量子动力学方程（QKE）。从表面上看，这似乎是一个过于简单的系统，但可以将其他线性两态系统映射到主动疾病系统上。在早期的宇宙中，我们发现QKE的解决方案通过绝热近似很好地描述，其中密度运算符的非对角线术语在短（振荡和/或散射）的时间表上是恒定的，但可能会在长（扩展）时间标度上缓慢发展。这种“量子动力学平衡”是随着相位平衡的量子发展而达到的。在这项工作中，我们介绍并评估了这种平衡ANSATZ，因为中微子状态在早期宇宙中以非零的Lepton数在早期的宇宙中发展，从而引起了散射诱导的活动性中微子转化的水平交叉。
We solved the Quantum Kinetic Equations (QKEs) for an active-sterile neutrino system in the early universe. While on the surface this may seem to be an overly simplistic system, other linear two-state systems can be mapped onto the active-sterile system. In the early universe, we find that solutions to the QKEs are well described by an adiabatic approximation where the off-diagonal terms of the density operator are constant on short (oscillation and/or scattering) timescales, but may slowly evolve on long (expansion) timescales. This "quantum kinetic equilibrium" attains as the quantum development of phase balances with the kinetic destruction of phase. In this work, we introduce and assess this equilibrium ansatz as the neutrino states evolve in the early universe with a non-zero lepton number, engendering level crossings that result in scattering-induced active-sterile neutrino transformation.
