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Co-amenability and Connes’s embedding problem

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Abstract

A longstanding open question of Connes asks whether any finite von Neumann algebra embeds into an ultraproduct of finite-dimensional matrix algebras. As of yet, algebras verified to satisfy the Connes’s embedding property belong to just a few special classes (e.g., amenable algebras and free group factors). In this article, we prove that von Neumann algebras satisfying Popa’s co-amenability have Connes’s embedding property.

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Correspondence to JinSong Wu.

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Wu, J. Co-amenability and Connes’s embedding problem. Sci. China Math. 55, 977–984 (2012). https://doi.org/10.1007/s11425-012-4369-z

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