德西特空間 數學與物理學中一個n維德西特空間英語de Sitter space標作dSn為一最大對稱的勞侖茲流形具有正常數的純量曲率 主要應用是在廣義相對論作為最簡單的宇宙數學模型 德西特是以威廉德西特為名他與阿爾伯特愛因斯坦於年代一同研究宇宙中的時空結構 以廣義相對論的語言來說德西特空間為愛因斯坦場方程式的最大對稱真空解具正宇宙學常數 Λ displaystyle Lambda  對應正真空能量密度和負壓 已隱藏部分未翻譯内容歡迎參與翻譯 In mathematical physics英语mathematical physics ndimensional de Sitter space often abbreviated to dSn is a maximally symmetric Lorentzian manifold英语Lorentzian manifold with constant positive scalar curvature英语scalar curvature It is the Lorentzian analogue of an nsphere英语nsphere with its canonical Riemannian metric英语Riemannian metric The main application of de Sitter space is its use in general relativity英语general relativity where it serves as one of the simplest mathematical models of the universe consistent with the observed accelerating expansion of the universe英语accelerating expansion of the universe More specifically de Sitter space is the maximally symmetric vacuum solution英语vacuum solution of Einsteins field equations英语Einsteins field equations with a positive cosmological constant英语cosmological constant Λ displaystyle Lambda  corresponding to a positive vacuum energy density and negative pressure There is cosmological evidence that the universe itself is asymptotically de Sitter英语de Sitter universe ie it will evolve like the de Sitter universe in the far future when dark energy英语dark energy dominates de Sitter space and antide Sitter space英语antide Sitter space are named after Willem de Sitter英语Willem de Sitter  professor of astronomy at Leiden University and director of the 莱顿天文台 Willem de Sitter and Albert Einstein worked closely together in Leiden in the s on the spacetime structure of our universe de Sitter space was also discovered independently and about the same time by 图利奥列维齐维塔