论文标题
环状因果集合宇宙学的观察力
Observables for cyclic causal set cosmologies
论文作者
论文摘要
在因果集理论中，宇宙膨胀和崩溃的循环是由带有“断裂”和“柱子”的因果集建模的，并且循环动力学扮演了特殊的作用，在这种动力学中，宇宙通过永久循环。我们识别并表征了两个可观察到的循环动力学的代数，其中因果集宇宙具有无限的突破。第一个代数是由与有限的因果集相关的圆柱集构建的，这些因果关系集具有单个最大元素，并提供了一个新框架，用于定义环状动力学，因为随机步行在新的树上。第二个代数是由词干组的集合生成的，并在这些模型中对观察力的物理解释作为有关单个最大元素的未标记词干的陈述。有类似的定理用于环状动力学，其中因果集宇宙具有无限的帖子。
In causal set theory, cycles of cosmic expansion and collapse are modelled by causal sets with "breaks" and "posts" and a special role is played by cyclic dynamics in which the universe goes through perpetual cycles. We identify and characterise two algebras of observables for cyclic dynamics in which the causal set universe has infinitely many breaks. The first algebra is constructed from the cylinder sets associated with finite causal sets that have a single maximal element and offers a new framework for defining cyclic dynamics as random walks on a novel tree. The second algebra is generated by a collection of stem-sets and offers a physical interpretation of the observables in these models as statements about unlabeled stems with a single maximal element. There are analogous theorems for cyclic dynamics in which the causal set universe has infinitely many posts.
