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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References
Connes A. Classification of injective factors, Cases II1, II∞, IIIλ, λ ≠ 1. Ann Math, 1976, 104: 73–115
Capraro V, Păunescu L. Product between ultrafilters and applications to the Connes’s embedding problem. arXiv:math/0911.4978v4, 2009
Collins B, Dykenma K. A linearization of Connes’ embedding problem. New York J Math, 2008, 14: 617–641
Elek G, Szabó E. Hyperlinearity, essentially free actions and L2-invariant. Math Ann, 2005, 332: 421–441
Ge L, Hadwin D. Ultraproducts of C*-algebras. Oper Theory Adv Appl, 2001, 127, 305–326
Janssen G. Restricted ultraproducts of finite von Neumann algebras. In: Studies in Logic and Found Math. Amsterdam: North-Holland, 1972, 101–114
Jones V. Index for subfactors. Invent Math, 1983, 72: 1–25
Haagerup U. The standard form of von Neumann algebras. Math Scand, 1975, 37: 271–285
Hadwin D. A noncommutative moment problem. Proc Amer Math Soc, 2001, 129: 1785–1791
Kadison R, Ringrose J. Fundamentals of the Operator Algebras I and II. Orlando: Academic Press, 1983 and 1986
Kirchberg E. On non-semisplit extensions, tensor products and exactness of group C* alegbras. Invent Math, 1993, 112: 449–489
Lance E C. On nuclear C* algebras. J Funct Anal, 1973, 12: 157–176
McDuff D. Central sequences and the hyperfinite factor. Proc London Math Soc, 1970, 21: 443–461
Murray F, von Neumann J. On rings of operators, IV. Ann Math, 1943, 44: 716–808
Monod N, Popa S. On co-amenable for groups and von Neumann algebras. arXiv: math/0301348, 2003
Ozawa N. About QWEP conjecture. Internat J Math, 2004, 15: 501–530
Pestov V. Hyperlinear and sofic groups: A brief guide. Bull Symbolic Logic, 2008, 14: 449–480
Popa S. Correspondences. INCREST preprint, 1986
Popa S. Some properties of the symmetric enveloping algebra of a subfactor, with appliactions to amenability and property T. Doc Math, 1999, 4: 665–744
Powers R, Størmer E. Free states of the canonical anti-commutation relations. Commun Math Phys, 1970, 16: 1–33
Rădulescu F. The von Neumann algebra of the non-residually finite Baumslag group 〈a, b|ab 3 a −1 = b 2〉 embeds into \(\mathcal{R}^\omega\). ArXiv:math/0004172, 2002
Sakai S. The theory of W*-algebras. Lectures Notes, Yale University, 1962
Sinclair A, Smith R. Finite von Neumann Algebras and Masas. Lodon: London Math Soc, 2008
Takesaki M. Theory of Operator Algebras I, II and III. Ency Math Sci. Cambridge: Cambridge University Press, 1983 and 2002
Wright F. A reduction for algebras of finite type. Ann Math, 1954, 60: 560–570
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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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DOI: https://doi.org/10.1007/s11425-012-4369-z