标题： 环量子宇宙学的一致历史方法 显示英文标题

标题： The consistent histories approach to loop quantum cosmology

摘要： 我们回顾量子理论的一致（或退相干）历史表述在规范圈量子宇宙学中的应用。 传统量子理论关键地依赖于“测量”，将未实现的量子可能性转化为可以赋予概率的物理结果。 在早期宇宙以及其他没有观察者或测量装置（甚至在任何封闭量子系统中）的物理情境中，是什么标准决定了哪些替代结果可以实现以及它们的概率是多少？ 在一致历史表述中，是描述替代历史的分支波函数之间的干涉消失——由系统的退相干泛函确定——决定了哪些替代结果可以赋予概率。 我们描述了一致历史表述及其如何应用于规范圈量子宇宙学，详细描述了其在具有标量物质的均匀和各向同性宇宙模型中的应用。 我们展示了在没有“观察者”的情况下，该理论如何用于做出明确的物理预测。 作为应用，我们证明了该理论预测圈量子模型从大体积到大体积“反弹”，而传统的“惠勒-德威特”量子化宇宙总是存在奇点。 我们还简要指出了与其他工作的关系。 显示英文摘要

摘要： We review the application of the consistent (or decoherent) histories formulation of quantum theory to canonical loop quantum cosmology. Conventional quantum theory relies crucially on "measurements" to convert unrealized quantum potentialities into physical outcomes that can be assigned probabilities. In the early universe and other physical contexts in which there are no observers or measuring apparatus (or indeed, in any closed quantum system), what criteria determine which alternative outcomes may be realized and what their probabilities are? In the consistent histories formulation it is the vanishing of interference between the branch wave functions describing alternative histories -- as determined by the system's decoherence functional -- that determines which alternatives may be assigned probabilities. We describe the consistent histories formulation and how it may be applied to canonical loop quantum cosmology, describing in detail the application to homogeneous and isotropic cosmological models with scalar matter. We show how the theory may be used to make definite physical predictions in the absence of "observers". As an application, we demonstrate how the theory predicts that loop quantum models "bounce" from large volume to large volume, while conventional "Wheeler-DeWitt"-quantized universes are invariably singular. We also briefly indicate the relation to other work.