发表机构
Swansea University; Cardiff University（斯旺西大学; 卡迪夫大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文介绍德西特时空的几何、因果结构与量子场论，涵盖坐标系、对称性、粒子产生及宇宙学扰动，强调曲率对质量、真空和可观测量的影响。
AI 中文摘要
德西特时空在现代宇宙学中扮演核心角色，为暴胀和当前加速膨胀提供了极佳的近似。它也提供了一个特别简单的环境，其中引力、时空对称性和量子场论在性质上不同于其闵可夫斯基空间对应物。这些讲义介绍德西特时空，从几何和对称性到固定3+1维德西特背景上的量子场和扰动。我们涵盖坐标系、因果结构、酉表示、时变背景中的粒子产生以及宇宙学扰动，强调物理解释、在宇宙学中的应用，以及曲率如何重塑质量、真空、粒子和晚期时间可观测量的概念。
英文摘要
de~Sitter spacetime plays a central role in modern cosmology, providing an excellent approximation to both inflation and the present accelerated expansion. It also offers a particularly simple setting in which gravity, spacetime symmetry, and quantum field theory depart qualitatively from their Minkowski-space counterparts. These lecture notes introduce de Sitter spacetime, from its geometry and symmetries to quantum fields and perturbations on a fixed \(3+1\)-dimensional de Sitter background. We cover coordinate systems, causal structure, unitary representations, particle production in time-dependent backgrounds, and cosmological perturbations, with emphasis on physical interpretation, applications to cosmology, and how curvature reshapes the notions of mass, vacuum, particles, and late-time observables.
Comments60 pages, 13 figs. Lecture notes based on lectures delivered at DESY in February 2026
