篇名 | Applications of von Neumann Algebras to Rigidity Problems of (2-step) Riemannian (Nil-)Manifolds |
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卷期 | 33:1 |
作者 | Hamid-Reza Fana¨ı 、 Atefeh Hasan-Zadeh |
頁次 | 056-061 |
關鍵字 | Von Neumann algebras 、 2-step nilmanifolds 、 Free and ergodic actions 、 Derivations 、 Automorphisms 、 Scopus |
出刊日期 | 201907 |
In this paper, basic notions of von Neumann algebra and its direct analogous in the realm of groupoids and measure spaces have been considered. By recovering the action of a locally compact Lie group from a crossed product of a von Neumann algebra, other proof of one of a geometric proposition of O’Neil and an extension of it has been proposed. Also, using the advanced exploration of nilmanifolds in measure spaces and their corresponding automorphisms (Lie algebraic derivations) a different proof of an analytic proposition of Gordon and Mao has been attained. These two propositions are of the most important ones for rigidity problems of Riemannian manifolds especially 2-step nilmanifolds.