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Transactions of the American Mathematical Society
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A Connes-amenable, dual Banach algebra need not have a normal, virtual diagonal

Author(s): Volker Runde
Journal: Trans. Amer. Math. Soc. 358 (2006), 391-402.
MSC (2000): Primary 46H20; Secondary 22A15, 22A20, 43A07, 43A10, 43A60, 46H25, 46M18, 46M20
Posted: July 26, 2005
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Abstract: Let $G$ be a locally compact group, and let $\mathcal{WAP}(G)$ denote the space of weakly almost periodic functions on $G$. We show that, if $G$ is a $[\operatorname{SIN}]$-group, but not compact, then the dual Banach algebra $\mathcal{WAP}(G)^\ast$ does not have a normal, virtual diagonal. Consequently, whenever $G$ is an amenable, non-compact $[\operatorname{SIN}]$-group, $\mathcal{WAP}(G)^\ast$ is an example of a Connes-amenable, dual Banach algebra without a normal, virtual diagonal. On the other hand, there are amenable, non-compact, locally compact groups $G$ such that $\mathcal{WAP}(G)^\ast$ does have a normal, virtual diagonal.


References:

[B-J-M]
J. F. BERGLUND, H. D. JUNGHENN, and P. MILNES, Analysis on Semigroups. Wiley-Interscience, 1988. MR 0999922 (91b:43001)

[B-P]
J. W. BUNCE and W. L. PASCHKE, Quasi-expectations and amenable von Neumann algebras. Proc. Amer. Math. Soc. 71 (1978), 232-236. MR 0482252 (58:2330)

[Bur]
R. B. BURCKEL, Weakly Almost Periodic Functions on Semigroups. Gordon and Breach, 1970. MR 0263963 (41:8562)

[Chou 1]
C. CHOU, Minimally weakly almost periodic groups. J. Funct. Anal. 36 (1980), 1-17. MR 0568972 (81f:43009)

[Chou 2]
C. CHOU, Weakly almost periodic functions and Fourier-Stieltjes algebras of locally compact groups. Trans. Amer. Math. Soc. 274 (1982), 141-157. MR 0670924 (84a:43008)

[Con 1]
A. CONNES, Classification of injective factors. Ann. of Math. 104 (1976), 73-114. MR 0454659 (56:12908)

[Con 2]
A. CONNES, On the cohomology of operator algebras. J. Funct. Anal. 28 (1978), 248-253. MR 0493383 (58:12407)

[C-G]
G. CORACH and J. E. GALÉ, Averaging with virtual diagonals and geometry of representations. In: E. ALBRECHT and M. MATHIEU (eds.), Banach Algebras '97, pp. 87-100. Walter de Grutyer, 1998.MR 1656600 (99m:46167)

[D-G-H]
H. G. DALES, F. GHAHRAMANI, and A. YA. HELEMSKISI, The amenability of measure algebras. J. London Math. Soc. (2) 66 (2002), 213-226. MR 1911870 (2003c:43001)

[Eff]
E. G. EFFROS, Amenability and virtual diagonals for von Neumann algebras. J. Funct. Anal. 78 (1988), 137-156. MR 0937636 (89e:46072)

[E-L]
E. G. EFFROS and E. C. LANCE, Tensor products of operator algebras. J. Funct. Anal. 25 (1977), 1-34.MR 0448092 (56:6402)

[E-K]
E. G. EFFROS and A. KISHIMOTO, Module maps and Hochschild-Johnson cohomology. Indiana Univ. Math. J. 36 (1987), 257-276.MR 0891774 (89b:46068)

[F-St]
S. FERRI and D. STRAUSS, A note on the $\mathcal{WAP}$-compactification and the $\mathcal{LUC}$-compactification of a topological group. Semigroup Forum 69 (2004), 87-101. MR 2063981

[Hel]
A. YA. HELEMSKISI, Homological essence of amenability in the sense of A. Connes: the injectivity of the predual bimodule (translated from the Russian). Math. USSR-Sb 68 (1991), 555-566.MR 1038222 (91f:46102)

[Joh 1]
B. E. JOHNSON, Separate continuity and measurability. Proc. Amer. Math. Soc. 20 (1969), 420-422. MR 0236345 (38:4641)

[Joh 2]
B. E. JOHNSON, Cohomology in Banach algebras. Mem. Amer. Math. Soc. 127 (1972). MR 0374934 (51:11130)

[Joh 3]
B. E. JOHNSON, Approximate diagonals and cohomology of certain annihilator Banach algebras. Amer. J. Math. 94 (1972), 685-698. MR 0317050 (47:5598)

[J-K-R]
B. E. JOHSON, R. V. KADISON, and J. RINGROSE, Cohomology of operator algebras, III. Bull. Soc. Math. France 100 (1972), 73-79. MR 0318908 (47:7454)

[Pat]
A. L. T. PATERSON, Amenability. American Mathematical Society, 1988. MR 0961261 (90e:43001)

[Ped]
G. K. PEDERSEN, $C^\ast$-Algebras and their Automorphism Groups. Academic Press, 1979. MR 0548006 (81e:46037)

[Run 1]
V. RUNDE, Amenability for dual Banach algebras. Studia Math. 148 (2001), 47-66. MR 1881439 (2002m:46078)

[Run 2]
V. RUNDE, Lectures on Amenability. Lecture Notes in Mathematics 1774, Springer Verlag, 2002. MR 1874893 (2003h:46001)

[Run 3]
V. RUNDE, Connes-amenability and normal, virtual diagonals for measure algebras, I. J. London Math. Soc. 67 (2003), 643-656.MR 1967697 (2004c:43003)

[Run 4]
V. RUNDE, Connes-amenability and normal, virtual diagonals for measure algebras, II. Bull. Austral. Math. Soc. 68 (2003), 325-328. MR 2016307 (2004j:43002)

[Run 5]
V. RUNDE, Dual Banach algebras: Connes-amenability, normal, virtual diagonals, and injectivity of the predual bimodule. Math. Scand. 95 (2004), 124-144. MR 2091485

[Was 1]
S. WASSERMANN, On Tensor products of certain group $C^*$-algebras. J. Funct. Anal. 23 (1976), 239-254. MR 0425628 (54:13582)

[Was 2]
S. WASSERMANN, Injective $W^\ast$-algebras. Math. Proc. Cambridge Phil. Soc. 82 (1977), 39-47. MR 0448108 (56:6418)


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Additional Information:

Volker Runde
Affiliation: Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2G1
Email: vrunde@ualberta.ca

DOI: 10.1090/S0002-9947-05-03827-4
PII: S 0002-9947(05)03827-4
Keywords: Locally compact groups, Connes-amenability, normal, virtual diagonals, weakly almost periodic functions, semigroup compactifications, minimally weakly almost periodic groups
Received by editor(s): October 26, 2003
Received by editor(s) in revised form: June 1, 2004
Posted: July 26, 2005
Copyright of article: Copyright 2005, American Mathematical Society
The copyright for this article reverts to public domain after 28 years from publication.


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