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$B^p_r(F_n)$ HAS NO NONTRIVIAL IDEMPOTENTS

Published online by Cambridge University Press:  06 October 2022

YIFAN LIU*
Affiliation:
Research Center for Operator Algebras, School of Mathematical Sciences, East China Normal University, Shanghai 200062, PR China
JIANGUO ZHANG
Affiliation:
School of Mathematics and Statistics, Shaanxi Normal University, Xi’an 710119, PR China e-mail: jgzhang15@163.com

Abstract

We show that there is no nontrivial idempotent in the reduced group $\ell ^p$-operator algebra $B^p_r(F_n)$ of the free group $F_n$ on n generators for each positive integer n.

Type
Research Article
Copyright
© The Author(s), 2022. Published by Cambridge University Press on behalf of Australian Mathematical Publishing Association Inc.

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Footnotes

The second author is supported by NSFC (No. 12171156).

References

Baum, P., Connes, A. and Higson, N., ‘Classifying space for proper actions and $K$ -theory of group ${C}^{\ast }$ -algebras’, in: ${C}^{\ast }$ -Algebras: 1943–1993, Contemporary Mathematics, 167 (ed. Doran, R. S.) (American Mathematical Society, Providence, RI, 1994), 240291.Google Scholar
Cohen, J. M. and Figà-Talamanca, A., ‘Idempotents in the reduced ${C}^{\ast }$ -algebra of a free group’, Proc. Amer. Math. Soc. 103(3) (1988), 779782.Google Scholar
Connes, A., ‘Noncommutative differential geometry’, Publ. Math. Inst. Hautes Études Sci. 62 (1985), 41144.CrossRefGoogle Scholar
Connes, A. and Moscovici, H., ‘Cyclic cohomology, the Novikov conjecture and hyperbolic groups’, Topology 29(3) (1990), 345388.CrossRefGoogle Scholar
de la Harpe, P., ‘Groupes hyperboliques, algèbres d’opérateurs et un théorème de Jolissaint’, C. R. Math. Acad. Sci. Paris 307(14) (1988), 771774.Google Scholar
Gardella, E. and Thiel, H., ‘Representations of $p$ -convolution algebras on ${L}_q$ -spaces’, Trans. Amer. Math. Soc. 371(3) (2019), 22072236.CrossRefGoogle Scholar
Gardella, E. and Thiel, H., ‘Isomorphisms of algebras of convolution operators’, Ann. Sci. Éc. Norm. Supér. (4), to appear.Google Scholar
Haagerup, U., ‘An example of a nonnuclear ${C}^{\ast }$ -algebra, which has the metric approximation property’, Invent. Math. 50(3) (1978), 279293.CrossRefGoogle Scholar
Hejazian, S. and Pooya, S., ‘Simple reduced ${L}_p$ -operator crossed products with unique trace’, J. Operator Theory 74(1) (2015), 133147.CrossRefGoogle Scholar
Higson, N. and Kasparov, G.. ‘ $E$ -theory and ${KK}$ -theory for groups which act properly and isometrically on Hilbert space’, Invent. Math. 144(1) (2001), 2374.CrossRefGoogle Scholar
Jolissaint, P., ‘Rapidly decreasing functions in reduced ${C}^{\ast }$ -algebras of groups’, Trans. Amer. Math. Soc. 317(1) (1990), 167196.Google Scholar
Lafforgue, V., ‘A proof of property (RD) for cocompact lattices of ${\mathrm{SL}}(3,\mathbb{R})$ and ${\mathrm{SL}}(3,\mathbb{C})$ ’, J. Lie Theory 10(2) (2000), 255267.Google Scholar
Lafforgue, V., ‘ $K$ -théorie bivariante pour les algèbres de Banach et conjecture de Baum–Connes’, Invent. Math. 149(1) (2002), 195.CrossRefGoogle Scholar
Liao, B. and Yu, G., $`K$ -theory of group Banach algebras and Banach property RD’, Preprint, 2017, arXiv:1708.01982.Google Scholar
Mineyev, I. and Yu, G., ‘The Baum–Connes conjecture for hyperbolic groups’, Invent. Math. 149(1) (2002), 97122.CrossRefGoogle Scholar
Phillips, N. C., ‘Crossed products of ${L}_p$ operator algebras and the $K$ -theory of Cuntz algebras on ${L}_p$ spaces’, Preprint, 2013, arXiv:1309.6406.Google Scholar
Phillips, N. C., ‘Simplicity of reduced group Banach algebras’, Preprint, 2019, arXiv:1909.11278.Google Scholar
Phillips, N. C., ‘Open problems related to operator algebras on ${L}_p$ spaces’. https://tinyurl.com/phillips-pdf.Google Scholar
Pimsner, M. and Voiculescu, D., ‘ $K$ -groups of reduced crossed products by free groups’, J. Operator Theory 8(1) (1982), 131156.Google Scholar
Puschnigg, M., ‘The Kadison–Kaplansky conjecture for word-hyperbolic groups’, Invent. Math. 149(1) (2002), 153194.CrossRefGoogle Scholar
Schweitzer, L. B., ‘A short proof that ${M}_n(A)$ is local if $A$ is local and Fréchet’, Internat. J. Math. 3(4) (1992), 581589.CrossRefGoogle Scholar