Home Spectral gap characterization of full type III factors
Article
Licensed
Unlicensed Requires Authentication

Spectral gap characterization of full type III factors

  • Amine Marrakchi EMAIL logo
Published/Copyright: January 12, 2017

Abstract

We give a spectral gap characterization of fullness for type III factors which is the analog of a theorem of Connes in the tracial case. Using this criterion, we generalize a theorem of Jones by proving that if M is a full factor and σ:GAut(M) is an outer action of a discrete group G whose image in Out(M) is discrete, then the crossed product von Neumann algebra MσG is also a full factor. We apply this result to prove the following conjecture of Tomatsu–Ueda: the continuous core of a type III1 factor M is full if and only if M is full and its τ invariant is the usual topology on .

Award Identifier / Grant number: GAN 637601

Funding statement: The research is supported by ERC Starting Grant GAN 637601.

Acknowledgements

We are very grateful to our advisor Cyril Houdayer for attracting our attention to this problem and for his help and suggestions throughout this work. We also thank Yoshimichi Ueda for explaining to us [15, Lemma 6] and for his useful comments.

References

[1] H. Ando and U. Haagerup, Ultraproducts of von Neumann algebras, J. Funct. Anal. 266 (2014), no. 12, 6842–6913. 10.1016/j.jfa.2014.03.013Search in Google Scholar

[2] A. Connes, Almost periodic states and factors of type III1, J. Funct. Anal. 16 (1974), no. 4, 415–445. 10.1016/0022-1236(74)90059-7Search in Google Scholar

[3] A. Connes, Classification of injective factors cases II1, II, IIIλ, λ1, Ann. of Math. (2) 104 (1976), 73–115. 10.2307/1971057Search in Google Scholar

[4] A. Connes, Factors of type III1, property Lλ and closure of inner automorphisms, J. Operator Theory 14 (1985), 189–211. Search in Google Scholar

[5] A. Connes and E. Størmer, Homogeneity of the state space of factors of type III1, J. Funct. Anal. 28 (1978), no. 2, 187–196. 10.1016/0022-1236(78)90085-XSearch in Google Scholar

[6] J. Dixmier and O. Maréchal, Vecteurs totalisateurs d’une algèbre de von Neumann, Comm. Math. Phys. 22 (1971), no. 1, 44–50. 10.1007/BF01651583Search in Google Scholar

[7] U. Haagerup, Lp-spaces associated with an arbitrary von Neumann algebra, Algebres d’opérateurs et leurs applications en physique mathématique (Marseille 1977), Coll. Int. Centre Nat. Rech. Sci. 274, Editions du Centre National de la Recherche Scientifique, Paris (1979), 175–184. Search in Google Scholar

[8] U. Haagerup, Operator valued weights in von Neumann algebras. I, J. Funct. Anal. 32 (1979), no. 2, 175–206. 10.1016/0022-1236(79)90053-3Search in Google Scholar

[9] V. F. Jones, Central sequences in crossed products of full factors, Duke Math. J 49 (1982), no. 1, 29–33. 10.1215/S0012-7094-82-04903-1Search in Google Scholar

[10] H. Kosaki, Applications of uniform convexity of noncommutative Lp-spaces, Trans. Amer. Math. Soc. 283 (1984), no. 1, 265–282. 10.1090/S0002-9947-1984-0735421-6Search in Google Scholar

[11] S. Popa, On the classification of inductive limits of II1 factors with spectral gap, Trans. Amer. Math. Soc. 364 (2012), no. 6, 2987–3000. 10.1090/S0002-9947-2012-05389-XSearch in Google Scholar

[12] Y. Raynaud, On ultrapowers of non-commutative Lp-spaces, J. Operator Theory 48 (2002), no. 1, 41–68. Search in Google Scholar

[13] D. Shlyakhtenko, On the classification of full factors of type III, Trans. Amer. Math. Soc. 356 (2004), no. 10, 4143–4159. 10.1090/S0002-9947-04-03457-9Search in Google Scholar

[14] M. Takesaki, Operator algebras II, Springer, New York 2001. Search in Google Scholar

[15] R. Tomatsu and Y. Ueda, A characterization of fullness of continuous cores of type III1 free product factors, Kyoto J. Math 56 (2014), no. 3, 599–610. 10.1215/21562261-3600193Search in Google Scholar

Received: 2016-06-08
Revised: 2016-11-08
Published Online: 2017-01-12
Published in Print: 2019-08-01

© 2019 Walter de Gruyter GmbH, Berlin/Boston

Downloaded on 29.10.2025 from https://www.degruyterbrill.com/document/doi/10.1515/crelle-2016-0071/html
Scroll to top button