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A Note on Uniformly Bounded Cocycles into Finite Von Neumann Algebras

  • Remi Boutonnet (a1) and Jean Roydor (a1)

We give a short proof of a result of T. Bates and T. Giordano stating that any uniformly bounded Borel cocycle into a finite von Neumann algebra is cohomologous to a unitary cocycle. We also point out a separability issue in their proof. Our approach is based on the existence of a non-positive curvature metric on the positive cone of a finite von Neumann algebra.

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[1] Abramenko, P. and Brown, K. S., Buildings. Theory and applications. Graduate Texts in Mathematics, 248, Springer, New York, 2008.
[2] Anantharaman-Delaroche, C., Cohomology ofproperty (T) groupoids and applications. Ergodic Theory Dynam. Systems 25(2005), 9771013.
[3] Andruchow, E. and Larotonda, G., Nonpositively curved metric in the positive cone of a finite von Neumann algebra. J. London Math. Soc. (2) 74(2006), no. 1, 205218. http://dx.doi.Org/10.1112/S0024610706022848
[4] Bates, T. and Giordano, T., Bounded cocycles on finite von Neumann algebras. Internat. J. Math. 12(2001), no. 6, 743750.http://dx.doi.Org/10.1142/S0129167X0100085X
[5] Miglioli, M., Unitarization oj uniformly bounded subgroups infinite von Neumann algebras. Bull. Lond. Math. Soc. 46(2014), 12641266.http://dx.doi.Org/10.1112/blms/bdu080
[6] Vasilescu, E-H. and Zsidó, L., Uniformly bounded groups infinite W*-algebras. Acta Sei. Math.(Szeged) 36(1974), 189192.
[7] Zimmer, R. J., Compactness conditions on cocycles of ergodic transformation groups. J. London Math. Soc. (2) 15(1977), no. 1,155163.http://dx.doi.Org/10.1112/jlms/s2-15.1.55
[8] Zimmer, R. J., Ergodic theory and semisimple groups. Monographs in Mathematics, 81, Birkhäuser Verlag, Basel, 1984.
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Canadian Mathematical Bulletin
  • ISSN: 0008-4395
  • EISSN: 1496-4287
  • URL: /core/journals/canadian-mathematical-bulletin
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