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Similarity Degree of a Class of C\({^*}\)-Algebras

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Suppose that \({\mathcal {M}}\) is a countably decomposable type II\({_1}\) von Neumann algebra and \({\mathcal {A}}\) is a separable, non-nuclear, unital C\({^*}\)-algebra. We show that, if \({\mathcal {M}}\) has Property \({\Gamma}\), then the similarity degree of \({\mathcal {M}}\) is less than or equal to 5. If \({\mathcal {A}}\) has Property c\({^*}\)-\({\Gamma}\), then the similarity degree of \({\mathcal {A}}\) is equal to 3. In particular, the similarity degree of a \({\mathcal {Z}}\)-stable, separable, non-nuclear, unital C\({^*}\)-algebra is equal to 3.

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References

  1. Barnes B.: The similarity problem for representations of a B*-algebra. Mich. Math. J. 22, 25–32 (1975)

    Article  MATH  Google Scholar 

  2. Bunce J.W.: The similarity problem for representations of C\({^*}\)-algebras. Proc. Am. Math. Soc. 81, 409–414 (1981)

    MathSciNet  MATH  Google Scholar 

  3. Christensen E.: On nonselfadjoint representations of C\({^*}\)-algebras. Am. J. Math. 103, 817–833 (1981)

    Article  MATH  Google Scholar 

  4. Christensen E.: Extensions of derivations II. Math. Scand. 50, 111–122 (1982)

    MathSciNet  MATH  Google Scholar 

  5. Christensen E.: Similarities of II\({_1}\) factors with property \({\Gamma}\). J. Oper. Theory 15, 281–288 (1986)

    MATH  Google Scholar 

  6. Christensen E.: Finite von Neumann algebra factors with Property \({\Gamma}\). J. Funct. Anal. 186, 366–380 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  7. Christensen E., Pop F., Sinclair A.M., Smith R.R.: Hochschild cohomology of factors with property \({\Gamma}\). Ann. Math. 158, 635–659 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  8. Dixmier J.: Quelques propriétés des suites centrales dans les facteurs de type II\({_{1}}\). Invent. Math. 7, 215–225 (1969)

    Article  MathSciNet  MATH  Google Scholar 

  9. Haagerup U.: Solution of the similarity problem for cyclic representations of C\({^*}\)-algebras. Ann. Math. 118, 215–240 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  10. Hadwin D.: Dilation and Hahn decomposition for linear maps. Can. J. Math. 33, 826–839 (1981)

    Article  MathSciNet  MATH  Google Scholar 

  11. Hadwin D., Li W.: The similarity degree of some C\({^*}\)-algebras. Bull. Aust. Math. Soc. 89(1), 60–69 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  12. Hadwin, D., Shen, J.: A modified similarity degree for C\({^*}\)-algebras. (2012). arXiv:1211.4855v1 [math.OA]

  13. Jiang X., Su H.: On a simple unital projectionless C\({^*}\)-algebra. Am. J. Math. 121, 359–413 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  14. Johanesová M., Winter W.: The similarity degree for \({\mathcal{Z}}\)-stable C\({^*}\)-algebras. Bull. Lond. Math. Soc. 44(6), 1215–1220 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  15. Jones V., Sunder V.S.: Introduction to Subfactors. Cambridge University Press, Cambridge (1997)

    Book  MATH  Google Scholar 

  16. Kadison R.V.: On the orthogonalization of operator representations. Am. J. Math. 77, 600–620 (1955)

    Article  MathSciNet  MATH  Google Scholar 

  17. Kadison, R.V., Ringrose, J.R.: Fundamentals of the Theory of Operator Algebras I, II. Academic Press, Orlando, 1983 (1986)

  18. Li W.: The similarity degree of approximately divisible C\({^*}\)-algebras. Oper. Matrices 7(2), 425–430 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  19. Murray, F.J., von Neumann, J.: On rings of operators IV. Ann. Math. (2) 44, 716–808 (1943)

  20. Pisier G.: The similarity degree of an operator algebra. St. Petersburg Math. J. 10, 103–146 (1999)

    MathSciNet  Google Scholar 

  21. Pisier G.: Similarity problems and length. Taiwan. J. Math. 5, 1–17 (2001)

    MathSciNet  MATH  Google Scholar 

  22. Pisier G.: Remarks on the similarity degree of an operator algebra. Int. J. Math. 12, 403–414 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  23. Pisier G.: A similarity degree characterization of nuclear C\({^*}\)-algebras. Publ. Res. Inst. Math. Sci. 42(3), 691–704 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  24. Pop F.: The similarity problem for tensor products of certain C\({^*}\)-algebras. Bull. Aust. Math. Soc. 70(03), 385–389 (2004)

    Article  MATH  Google Scholar 

  25. Qian W., Shen J.: Hochschild cohomology of type II\({_{1}}\) von Neumann algebras with Property \({\Gamma}\). Oper. Matrices 9, 507–543 (2015)

    MathSciNet  Google Scholar 

  26. Qian, W., Hadwin, D., Shen, J.: Similarity degree of type II\({_1}\) von Neumann algebras with Property \({\Gamma}\). (2014). arXiv:1407.6929v4 [math.OA]

  27. Sakai S.: C\({^*}\)-algebras and W\({^*}\)-algebras. Springer, Berlin (1971)

    MATH  Google Scholar 

  28. von Neumann, J.: On rings of operators. Reduction theory. Ann. Math. 50, 401–485 (1949)

  29. Wittstock G.: Ein operatorwertiger Hahn-Banach Satz. J. Funct. Anal. 40, 127–150 (1981)

    Article  MathSciNet  MATH  Google Scholar 

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Correspondence to Wenhua Qian.

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The first author was supported by Research Center for Operator Algebras of East China Normal University.

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Qian, W., Shen, J. Similarity Degree of a Class of C\({^*}\)-Algebras. Integr. Equ. Oper. Theory 84, 121–149 (2016). https://doi.org/10.1007/s00020-015-2266-x

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