Abstract
We develop a new method, based on non-vanishing of second cohomology groups, for proving the failure of lifting properties for full C\(^*\)-algebras of countable groups with (relative) property (T). We derive that the full C\(^*\)-algebras of the groups \(\mathbb {Z}^2\times \text {SL}_2({\mathbb {Z}})\) and \(\text {SL}_n({\mathbb {Z}})\), for \(n\ge 3\), do not have the local lifting property (LLP). We also prove that the full C\(^*\)-algebras of a large class of groups \(\Gamma \) with property (T), including those such that \(\text {H}^2(\Gamma ,{\mathbb {R}})\not =0\) or \(\text {H}^2(\Gamma ,\mathbb {Z}\Gamma )\not =0\), do not have the lifting property (LP). More generally, we show that the same holds if \(\Gamma \) admits a probability measure preserving action with non-vanishing second \({\mathbb {R}}\)-valued cohomology. Finally, we prove that the full C\(^*\)-algebra of any non-finitely presented property (T) group fails the LP.
Similar content being viewed by others
References
T. Austin and C.C. Moore: Continuity properties of measurable group cohomology, Math. Ann. 356 (2013), no. 3, 885-937.
C. Anantharaman-Delaroche and S. Popa: An introduction to\(II_1\)factors, preprint, 2017.
A. Aaserud and S. Popa: Approximate equivalence of group actions, Ergod. Th. Dynam. Sys. 38 (2018), 1201-1237.
G. Baumslag: Lecture notes on nilpotent groups, Regional Conference Series in Mathe- matics, No. 2, American Mathematical Society, Providence, R.I., 1971.
B. Bekka, P. de la Harpe and A. Valette: Kazhdan’s property (T), New Mathematical Monographs, 11. Cambridge University Press, Cambridge, 2008.
M. B. Bekka: On the full\(C^*\)-algebras of arithmetic groups and the congruence subgroup problem, Forum Math. 11 (1999), no. 6, 705-715.
O. Becker and A. Lubotzky: Group stability and Property (T), J. Funct. Anal. 278 (2020), no. 1.
N. P. Brown and N. Ozawa: \(C^*\)-algebras and finite-dimensional approximations, Graduate Studies in Mathematics, vol. 88, American Mathematical Society, Providence, RI, 2008.
M. Burger: Kazhdan constants for\(SL (3,{\mathbb{Z}})\), J. Reine Angew. Math. 413 (1991), 36-67.
M.-D. Choi and E. G. Effros: The completely positive lifting problem for\(C^*\)-algebras, Ann. of Math. 104 (1976), 585-609.
A. Connes, J. Feldman and B. Weiss: An amenable equivalence relation is generated by a single transformation, Ergod. Th. Dynam. Sys. 1 (1981), 431-450.
M. De Chiffre, N. Ozawa and A. Thom: Operator algebraic approach to inverse and stability theorems for amenable groups, Mathematika, 65 (2019), 98-118.
K. Courtney: Universal\(C^*\)-algebras with the Local Lifting Property, preprint , 2020, to appear in Math. Scand.
P. de la Harpe: Topics in geometric group theory, The University of Chicago Press, 2000.
J. Feldman and C.C. Moore: Ergodic Equivalence Relations, Cohomology, and Von Neumann Algebras, I, Trans. Amer. Math. Soc. 234 (1977), 289-324.
D. Farenick, A. Kavruk, V.I. Paulsen and I.G. Todorov: Characterisations of the weak expectation property, New York Journal of Mathematics 24a (2018), 107-135.
A. Furman: Gromov’s measure equivalence and rigidity of higher rank lattices, Ann. of Math. (2) 150 (1999), 1059-1081.
A. Furman: Orbit equivalence rigidity, Ann. of Math. (2) 150 (1999), 1083-1108.
D. Hadwin and T. Shulman: Stability of group relations under small Hilbert-Schmidt perturbations, J. Funct. Anal. 275 (2018), no. 4, 761-792.
A. Ioana: Orbit inequivalent actions for groups containing a copy of\({\mathbb{F}} _2\), Invent. Math., 185 (2011), 55-73.
P. Jolissaint: On property (T) for pairs of topological groups, Enseign. Math. (2) 51 (2005), 31-45.
M. Junge and G. Pisier: Bilinear forms on exact operator spaces and\(B(H) \otimes B(H)\), Geom. Funct. Anal. 5 (1995), no. 2, 329-363.
Y. Jiang: A remark on \({\mathbb{T}}\)-valued cohomology groups ofalgebraic group actions, J. Funct. Anal. 271 (2016), 577-592.
D. Kazhdan: Connection of the dual space of a group with the structure of its closed subgroups, Funct. Anal. Appl. 1 (1967) 63-65.
G. G. Kasparov: Hilbert \(C^*\)-modules: theorems of Stinespring and Voiculescu, J. Operator Theory 4 (1980), no. 1, 133-150.
A.S. Kechris: Topology and descriptive set theory, Topology Appl. 58 (1994), no. 3, 195-222.
E. Kirchberg: On nonsemisplit extensions, tensor products and exactness of group\(C^*\)-algebras, Invent. Math. 112 (1993), 449-489.
E. Kirchberg: Discrete groups with Kazhdan’s property T and factorization property are residually finite, Math. Ann. 299 (1994), no. 3, 551-563.
E. Kirchberg: Commutants of unitaries in UHF algebras and functorial properties of exactness, J. Reine Angew. Math. 452 (1994), 39-77.
Y. Kida: Splitting in orbit equivalence, treeable groups, and the Haagerup property, In: Hyperbolic geometry and geometric group theory, 167-214, Adv. Stud. Pure Math., 73, Math. Soc. Japan, Tokyo, 2017.
C. Lance: On nuclear\(C^*\)-algebras, J. Funct. Analysis, 12 (1973), 157-176.
W. Luck: Approximating\(L^2\)-invariants by their finite-dimensional analogues, Geom. Funct. Anal., 4 (1994), no. 4, 455-481.
G. Margulis: Finitely-additive invariant measures on Euclidean spaces, Ergodic Theory Dynam. Systems 2 (1982) 383-396.
C.C. Moore: Group extensions and cohomology for locally compact groups, III. Trans. Amer. Math. Soc. 221 (1976), no. 1, 1-33.
C. C. Moore: Group extensions and cohomology for locally compact groups. IV, Trans. Amer. Math. Soc. 221 (1976), no. 1, 35-58.
C. C. Moore and K. Schmidt: Coboundaries and Homomorphisms for Non-Singular Actions and a Problem of H. Helson, Proc. Lond. Math. Soc., 40 (1980), 443-475.
S. Morris: Pontryagin duality and the structure of locally compact abelian groups, Cambridge University Press, Vol. 29, 1977.
R. Nicoara, S. Popa and R. Sasyk: On\(II_1\)factors arising from 2-cocycles of w-rigid groups, J. Funct. Analysis, 242 (2007), 230-246.
Y. Ollivier: A January 2005 Invitation to Random Groups, Ensaios Matemáticos (Mathematical Surveys), vol.10, Sociedade Brasileira de Matemática, Rio de Janeiro, 2005.
N. Ozawa: There is no separable universal\(II_1\)factor, Proc. Amer. Math. Soc., 132 (2004), 487-490.
N. Ozawa: About the QWEP conjecture, Internat. J. Math., 15 (2004), 501-530.
N. Ozawa: Tsirelson’s problem and asymptotically commuting unitary matrices, J. Math. Phys., 54 (2013), 032202 (8 pages).
G. Pisier: A simple proof of a theorem of Kirchberg and related results on\(C^*\)-norms, J. Operator Theory 35 (1996), no. 2, 317-335.
G. Pisier: Remarks on \(B(H)\otimes B(H)\), Proc. Indian Acad. Sci. (Math. Sci.) 116 (2006), 423-428.
G. Pisier: A non-nuclear\(C^*\)-algebra with the Weak Expectation Property and the Local Lifting Property, preprint , 2019, to appear in Invent. Math.
G. Pisier: Tensor Products of\(C^*\)-Algebras and Operator Spaces: The Connes-Kirchberg Problem (London Mathematical Society Student Texts). Cambridge: Cambridge University Press. https://doi.org/10.1017/9781108782081.
S. Popa: Correspondences, INCREST Preprint, 56/1986, available on the author’s website: https://www.math.ucla.edu/~popa/popa-correspondences.pdf.
S. Popa: Cocycle and orbit equivalence superrigidity for malleable actions of w-rigid groups, Invent. Math. 170 (2007), 243-295.
S. Popa: Deformation and rigidity for group actions and von Neumann algebras, In Proceedings of the International Congress of Mathematicians (Madrid, 2006), Vol. I, European Mathematical Society Publishing House, 2007, p. 445-477.
S. Popa: On the superrigidity of malleable actions with spectral gap, J. Amer. Math. Soc. 21 (2008), 981-1000.
J. Peterson and T. Sinclair: On cocycle superrigidity for Gaussian actions, Ergodic Theory Dynam. Systems 32 (2012), no. 1, 249-272.
K. Schmidt: Amenability, Kazhdan’s property T, strong ergodicity and invariant means for ergodic group-actions, Ergodic Theory Dynam. Systems 1 (1981), no. 2, 223-236.
Y. Shalom: Bounded generation and Kazhdan’s Property (T), Publ. Math. IHES, 90,145-168, 1999.
Y. Shalom: Rigidity of commensurators and irreducible lattices, Invent. Math., 141,1-54, 2000.
T. Sinclair: Strong solidity of group factors from lattices in\(\text{ SO }(n, 1)\)and\(\text{ SU }(n, 1)\), J. Funct. Analysis, 260, nr. 11 (2011), 3209-3221.
C. Soulé: The cohomology of\(\text{ SL}_3({\mathbb{Z}})\), Topology 17, Issue 1, 1978, 1-22.
M. Takesaki: Theory of Operator Algebras I, ser. Encyclopaedia of Mathematical Sciences. Springer, 124, 2001. xix+415 pp.
A. Thom, Examples of hyperlinear groups without factorization property, Groups Geom. Dyn. 4 (2010), no. 1, 195-208.
R. Zimmer: Ergodic theory and semisimple groups, Monographs in Mathematics, 81. Birkhäuser Verlag, Basel, 1984. x+209 pp.
Acknowledgements
We would like to thank Sorin Popa for helpful comments.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
A.I. was supported in part by NSF Career Grant DMS #1253402 and NSF FRG Grant #1854074.
Rights and permissions
About this article
Cite this article
Ioana, A., Spaas, P. & Wiersma, M. Cohomological obstructions to lifting properties for full C\(^*\)-algebras of property (T) groups. Geom. Funct. Anal. 30, 1402–1438 (2020). https://doi.org/10.1007/s00039-020-00550-4
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00039-020-00550-4