[Rigidité pour les shifts de Bernoulli et leurs algèbres de von Neumann]
Par des méthodes très originales d’algèbres d’opérateurs, Sorin Popa a démontré que si un groupe ayant la propriété (T) de Kazhdan agit par shift de Bernoulli, alors la partition en orbites se souvient entièrement du groupe et de l’action. Ces informations sont même essentiellement retenues par l’algèbre de von Neumann de ce système dynamique, ce qui constitue dans la littérature le premier résultat de rigidité forte pour les algèbres de von Neumann. Avec ces mêmes méthodes, Popa construit également des facteurs de type II ayant un groupe fondamental dénombrable arbitraire.
Using very original methods from operator algebras, Sorin Popa has shown that the orbit structure of the Bernoulli action of a property (T) group, completely remembers the group and the action. This information is even essentially contained in the crossed product von Neumann algebra. This is the first von Neumann strong rigidity theorem in the literature. The same methods allow Popa to obtain II factors with prescribed countable fundamental group.
Keywords: superrigidity, Bernoulli action, property (T), classification of von Neumann algebras, II$_1$ factor, fundamental group
Mot clés : superrigidité, shift de Bernoulli, propriété (T), classification d’algèbres de von Neumann, facteur II$_1$, groupe fondamental
@incollection{SB_2005-2006__48__237_0, author = {Vaes, Stefaan}, title = {Rigidity results for {Bernoulli} actions and their von {Neumann} algebras}, booktitle = {S\'eminaire Bourbaki : volume 2005/2006, expos\'es 952-966}, series = {Ast\'erisque}, note = {talk:961}, pages = {237--294}, publisher = {Soci\'et\'e math\'ematique de France}, number = {311}, year = {2007}, mrnumber = {2359046}, zbl = {1194.46085}, language = {en}, url = {http://www.numdam.org/item/SB_2005-2006__48__237_0/} }
TY - CHAP AU - Vaes, Stefaan TI - Rigidity results for Bernoulli actions and their von Neumann algebras BT - Séminaire Bourbaki : volume 2005/2006, exposés 952-966 AU - Collectif T3 - Astérisque N1 - talk:961 PY - 2007 SP - 237 EP - 294 IS - 311 PB - Société mathématique de France UR - http://www.numdam.org/item/SB_2005-2006__48__237_0/ LA - en ID - SB_2005-2006__48__237_0 ER -
%0 Book Section %A Vaes, Stefaan %T Rigidity results for Bernoulli actions and their von Neumann algebras %B Séminaire Bourbaki : volume 2005/2006, exposés 952-966 %A Collectif %S Astérisque %Z talk:961 %D 2007 %P 237-294 %N 311 %I Société mathématique de France %U http://www.numdam.org/item/SB_2005-2006__48__237_0/ %G en %F SB_2005-2006__48__237_0
Vaes, Stefaan. Rigidity results for Bernoulli actions and their von Neumann algebras, dans Séminaire Bourbaki : volume 2005/2006, exposés 952-966, Astérisque, no. 311 (2007), Exposé no. 961, pp. 237-294. http://www.numdam.org/item/SB_2005-2006__48__237_0/
[1] “An equivalence relation that is not freely generated”, Proc. Amer. Math. Soc. 102 (1988), no. 3, p. 565-566. | MR | Zbl
-[2] “Subalgebras of a finite algebra”, Math. Ann. 243 (1979), no. 1, p. 17-29. | EuDML | MR | Zbl
-[3] “Outer conjugacy classes of automorphisms of factors”, Ann. Sci. École Norm. Sup. (4) 8 (1975), no. 3, p. 383-419. | EuDML | Numdam | MR | Zbl
-[4] -, “Classification of injective factors. Cases II II III ”, Ann. of Math. (2) 104 (1976), no. 1, p. 73-115. | MR | Zbl
[5] -, “Periodic automorphisms of the hyperfinite factor of type II”, Acta Sci. Math. (Szeged) 39 (1977), no. 1-2, p. 39-66. | MR | Zbl
[6] -, “A factor of type II with countable fundamental group”, J. Operator Theory 4 (1980), no. 1, p. 151-153. | MR | Zbl
[7] -, “Classification des facteurs”, in Operator algebras and applications, Part 2 (Kingston, Ont., 1980), Proc. Sympos. Pure Math., vol. 38, Amer. Math. Soc., Providence, 1982, p. 43-109. | MR | Zbl
[8] -, “Indice des sous facteurs, algèbres de Hecke et théorie des nœuds [d'après Vaughan Jones]”, in Séminaire Bourbaki (1984/85), Astérisque, vol. 133-134, Soc. Math. France, Paris, 1986, p. 289-308. | Numdam | Zbl
[9] -, “Nombres de Betti et facteurs de type [d’après D. Gaboriau et S. Popa]”, in Séminaire Bourbaki (2002/2003), Astérisque, vol. 294, Soc. Math. France, Paris, 2004, p. 321-333. | Numdam | Zbl
[10] “An amenable equivalence relation is generated by a single transformation”, Ergodic Theory Dynam. Systems 1 (1981), p. 431-450. | DOI | MR | Zbl
, & -[11] “Property (T) for von Neumann algebras”, Bull. London Math. Soc. 17 (1985), p. 57-62. | DOI | MR | Zbl
& -[12] -, “A II factor with two nonconjugate Cartan subalgebras”, Bull. Amer. Math. Soc. (N.S.) 6 (1982), p. 211-212. | MR | Zbl
[13] “Entropy for automorphisms of II von Neumann algebras”, Acta Math. 134 (1975), p. 289-306. | DOI | MR | Zbl
& -[14] “Completely bounded multipliers of the Fourier algebra of a simple Lie group of real rank one”, Invent. Math. 96 (1989), p. 507-549. | DOI | EuDML | MR | Zbl
& -[15] “Sur les relations entre l'espace dual d'un groupe et la structure de ses sous-groupes fermés [d'après D. A. Kazhdan]”, in Séminaire Bourbaki, Astérisque, vol. 10, Soc. Math. France, Paris, 1995, exp. no. 343 (février 1968), p. 507-528. | EuDML | Numdam | MR | Zbl
& -[16] “On groups of measure preserving transformation. I”, Amer. J. Math. 81 (1959), p. 119-159. | DOI | MR | Zbl
-[17] -, “On groups of measure preserving transformations. II”, Amer. J. Math. 85 (1963), p. 551-576. | DOI | MR | Zbl
[18] “Interpolated free group factors”, Pacific J. Math. 163 (1994), no. 1, p. 123-135. | MR | Zbl
-[19] “Ergodic equivalence relations, cohomology, and von Neumann algebras, II”, Trans. Amer. Math. Soc. 234 (1977), p. 325-359. | DOI | MR | Zbl
& -[20] “Gromov's measure equivalence and rigidity of higher rank lattices”, Ann. of Math. (2) 150 (1999), no. 3, p. 1059-1081. | EuDML | MR | Zbl
-[21] -, “Orbit equivalence rigidity”, Ann. of Math. (2) 150 (1999), no. 3, p. 1083-1108. | EuDML | MR | Zbl
[22] “Invariants de relations d’équivalence et de groupes”, Publ. Math. Inst. Hautes Études Sci. (2002), no. 95, p. 93-150. | EuDML | Numdam | MR | Zbl
-[23] “Cohomology of the ergodic action of a -group on the homogeneous space of a compact Lie group”, in Operators in function spaces and problems in function theory, Naukova Dumka, Kiev, 1987, Russian, p. 77-83. | MR | Zbl
-[24] “T-property and nonisomorphic full factors of types II and III”, J. Funct. Anal. 70 (1987), p. 80-89. | DOI | MR | Zbl
& -[25] Coxeter graphs and towers of algebras, Springer-Verlag, New York, 1989. | DOI | MR | Zbl
, & -[26] La propriété (T) de Kazhdan pour les groupes localement compacts, Astérisque, vol. 175, Soc. Math. France, Paris, 1989. | Numdam | Zbl
& -[27] “A converse to Dye's theorem”, Trans. Amer. Math. Soc. 357 (2005), no. 8, p. 3083-3103 (electronic). | MR | Zbl
-[28] “Rigidity results for wreath product II factors”, preprint, math.OA/0606574. | MR | Zbl
-[29] “Amalgamated Free Products of -Rigid Factors and Calculation of their Symmetry Groups”, Acta Math., to appear; math.OA/0505589. | DOI | MR | Zbl
, & -[30] “On property (T) for pairs of topological groups”, Enseign. Math. (2) 51 (2005), no. 1-2, p. 31-45. | MR | Zbl
-[31] “Actions of finite groups on the hyperfinite type factor”, Mem. Amer. Math. Soc. 28 (1980), no. 237. | MR | Zbl
-[32] -, “A converse to Ocneanu's theorem”, J. Operator Theory 10 (1983), no. 1, p. 61-63. | MR | Zbl
[33] -, “Index for subfactors”, Invent. Math. 72 (1983), no. 1, p. 1-25. | EuDML | MR | Zbl
[34] “Problems on von Neumann algebras”, Baton Rouge Conference, 1967. | Zbl
-[35] Fundamentals of the theory of operator algebras II, Academic Press, Orlando, 1986. | MR | Zbl
& -[36] “Connection of the dual space of a group with the structure of its closed subgroups”, Funct. Anal. Appl. 1 (1967), p. 63-65. | DOI | MR | Zbl
-[37] “Finitely-additive invariant measures on Euclidean spaces”, Ergodic Theory Dynam. Systems 2 (1982), no. 3-4, p. 383-396 (1983). | MR | Zbl
-[38] -, Discrete subgroups of semisimple Lie groups, Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)], vol. 17, Springer-Verlag, Berlin, 1991. | MR | Zbl
[39] “Orbit equivalence rigidity and bounded cohomology”, Ann. of Math. (2) 164 (2006), p. 825-878. | MR | Zbl
& -[40] “Ergodic theory and von Neumann algebras”, in Operator algebras and applications, Part 2 (Kingston, Ont., 1980), Proc. Sympos. Pure Math., vol. 38, Amer. Math. Soc., Providence, 1982, p. 179-226. | MR | Zbl
-[41] “On rings of operators”, Ann. of Math. (2) 37 (1936), p. 116-229. | JFM | MR | Zbl
& -[42] -, “On rings of operators, IV”, Ann. of Math. (2) 44 (1943), p. 716-808. | MR | Zbl
[43] “Ergodic Theory and Maximal Abelian Subalgebras of the Hyperfinite Factor”, J. Funct. Anal. 195 (2002), p. 239-261. | DOI | MR | Zbl
& -[44] Actions of discrete amenable groups on von Neumann algebras, Lecture Notes in Mathematics, vol. 1138, Springer-Verlag, Berlin, 1985. | DOI | MR | Zbl
-[45] “Ergodic theory of amenable group actions”, Bull. Amer. Math. Soc. (N.S.) 2 (1980), p. 161-164. | MR | Zbl
& -[46] “Some prime factorization results for type II factors”, Invent. Math. 156 (2004), p. 223-234. | DOI | MR | Zbl
& -[47] “On the Notion of Relative Property (T) for Inclusions of Von Neumann Algebras”, J. Funct. Anal. 219 (2005), p. 469-483. | DOI | MR | Zbl
& -[48] “Cocycle and orbit equivalence superrigidity for malleable actions of -rigid groups”, Invent. Math., to appear; math.GR/0512646. | MR | Zbl
-[49] -, “Correspondences”, INCREST preprint, 1986. | Zbl
[50] -, “Sous-facteurs, actions des groupes et cohomologie”, C. R. Acad. Sci. Paris Sér. I Math. 309 (1989), no. 12, p. 771-776. | Zbl
[51] -, “On the fundamental group of type factors”, Proc. Natl. Acad. Sci. USA 101 (2004), no. 3, p. 723-726 (electronic). | MR | Zbl
[52] -, “On a class of type factors with Betti numbers invariants”, Ann. of Math. (2) 163 (2006), no. 3, p. 809-899. | MR | Zbl
[53] -, “Some computations of 1-cohomology groups and construction of non-orbit-equivalent actions”, J. Inst. Math. Jussieu 5 (2006), no. 2, p. 309-332. | MR | Zbl
[54] -, “Some rigidity results for non-commutative Bernoulli shifts”, J. Funct. Anal. 230 (2006), no. 2, p. 273-328. | MR | Zbl
[55] -, “Strong rigidity of II factors arising from malleable actions of -rigid groups, Part I”, Invent. Math. 165 (2006), p. 369-408. | DOI | MR | Zbl
[56] -, “Strong rigidity of II factors arising from malleable actions of -rigid groups, Part II”, Invent. Math. 165 (2006), p. 409-451. | DOI | MR | Zbl
[57] “On the cohomology of actions of groups by Bernoulli shifts”, Ergodic Dynam. Systems 27 (2007), p. 241-251. | DOI | MR | Zbl
& -[58] “Strong rigidity of generalized Bernoulli actions and computations of their symmetry groups”, preprint, math.OA/0605456. | MR | Zbl
& -[59] “The fundamental group of the von Neumann algebra of a free group with infinitely many generators is ”, J. Amer. Math. Soc. 5 (1992), no. 3, p. 517-532. | MR | Zbl
-[60] -, “Random matrices, amalgamated free products and subfactors of the von Neumann algebra of a free group, of noninteger index”, Invent. Math. 115 (1994), no. 2, p. 347-389. | EuDML | MR | Zbl
[61] “Measurable group theory”, in European Congress of Mathematics, Eur. Math. Soc., Zürich, 2005, p. 391-423. | MR | Zbl
-[62] “Finite subalgebras of a von Neumann algebra”, J. Funct. Anal. 25 (1977), no. 3, p. 211-235. | MR | Zbl
-[63] “Nouvelles approches de la propriété (T) de Kazhdan”, Astérisque, vol. 294, Soc. Math. France, Paris, 2004, p. 97-124. | EuDML | Numdam | MR | Zbl
-[64] “Circular and semicircular systems and free product factors”, in Operator algebras, unitary representations, enveloping algebras, and invariant theory (Paris 1989), Progr. Math., vol. 92, Birkhäuser Boston, Boston, MA, 1990, p. 45-60. | MR | Zbl
-[65] -, “The analogues of entropy and of Fisher's information measure in free probability theory. III. The absence of Cartan subalgebras”, Geom. Funct. Anal. 6 (1996), no. 1, p. 172-199. | EuDML | MR | Zbl
[66] “Strong rigidity for ergodic actions of semisimple Lie groups”, Ann. of Math. (2) 112 (1980), no. 3, p. 511-529. | MR | Zbl
-[67] -, Ergodic theory and semisimple groups, Monographs in Mathematics, vol. 81, Birkhäuser Verlag, Basel, 1984. | MR | Zbl
[68] -, “Groups generating transversals to semisimple Lie group actions”, Israel J. Math. 73 (1991), no. 2, p. 151-159. | MR | Zbl