发表机构
University of Bayreuth（拜罗伊特大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在开放量子系统框架下，通过构建含热扰动环境的半经典暴胀宇宙玩具模型，推导主方程，发现热贡献的退相干时标可短于哈勃时标，还探讨了退相干诱导指针态结构作为早期宇宙半经典态选择判据的可能性。
AI 中文摘要
我们在一个玩具模型中研究，在开放量子系统的框架下，将宇宙学扰动视为环境时，宇宙学扰动的热浴如何使宇宙的均匀自由度发生退相干。与若干早期方法不同，我们未从总波函数的半经典近似中迹去扰动，而是通过有效二阶耦合纳入其宇宙学反作用，并推导得到主方程。我们的玩具模型由处于慢滚 regime 的带时钟场的空间平坦半经典暴胀宇宙构成，而处于类热假设态的标量宇宙学扰动构成环境。该模型的特征之一是未采用马尔可夫近似。所得耦合常数由量子化扰动模式的热关联函数决定。在该框架内，我们发现，对于一组代表性参数估计，对应热贡献的特征退相干时标可短于哈勃时标。此外，我们探讨了在该框架下由退相干诱导的指针态结构是否可为早期宇宙半经典态的选择提供判据这一问题。
英文摘要
We study, within a toy model, how a thermal bath of cosmological perturbations can decohere the homogeneous degrees of freedom of the universe, treating the perturbations as an environment in the framework of open quantum systems. In contrast to several earlier approaches, instead of tracing out the perturbations from a semiclassical ansatz for the total wave function, we incorporate their cosmological backreaction through an effective second-order coupling and derive a master equation. Our toy model consists of a spatially flat semiclassical inflationary universe with a clock field in the slow-roll regime, while scalar cosmological perturbations in an assumed thermal-like state constitute the environment. One of the features of the model is the absence of the Markov approximation. The resulting coupling constant is determined by thermal correlation functions of the quantized perturbation modes. Within this framework, we find that, for a representative set of parameter estimates, the characteristic decoherence timescale corresponding to the thermal contribution can be shorter than the Hubble timescale. In addition, we address the question of whether the pointer-state structure induced by the decoherence in such a framework could provide a criterion for the choice of semiclassical states in the early universe.
