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Some new rigidity results for stable orbit equivalence

Published online by Cambridge University Press:  19 September 2008

Scot Adams
Affiliation:
Department of Mathematics, Vincent Hall 206 Church St, SE University of Minnesota Minneapolis, MN 55455, USA

Abstract

Broadly speaking, we prove that an action of a group with very little commutativity cannot be stably orbit equivalent to an action of a group with enough commutativity, assuming both actions are free and finite measure preserving. For example, one group may be SL2(ℝ) and the other a group with infinite discrete center (e.g., the universal cover of SL2(ℝ)); I believe this is the first rigidity result of this type for a pair of simpleLie groups both of split rank one. Another example: one group may be any nonelementary word hyperbolic group, the other any group with infinite discrete center.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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References

REFERENCES

[Ad1]Adams, S.. Indecomposability of treed equivalence relations. Israel J. Math. 64:3 (1988), 362380.Google Scholar
[Ad2]Adams, S.. Indecomposability of equivalence relations generated by word hyperbolic groups. To appear.Google Scholar
[Ad3]Adams, S.. Boundary amenability for word hyperbolic groups and an application to smooth dynamics of simple groups. Topology. To appear.Google Scholar
[Ad4]Adams, S.. Generalities on amenable actions. Preprint.Google Scholar
[Arv1]Arveson, W.. Invitation to C*-algebras. Springer: New York, 1976.Google Scholar
[Ch1]Champetier, C.. Propriétŕs statistiques des groupes de présentation finie. Preprint. 1992.Google Scholar
[FHM1]Feldman, J., Hahn, P. and Moore, C.. Orbit structure and countable sections for actions of continuous groups. Adv. Math. 28 (1978), 186230.Google Scholar
[FSZ1]Feldman, J., Sutherland, C. and Zimmer, R.. Subrelations of ergodic equivalence relations. Ergod. Th. & Dynam. Sys. 9 (1989), 239269.Google Scholar
[Fur1]Furstenberg, H.. Recurrence in Ergodic Theory and Combinatorial Number Theory. Princeton University Press: Princeton, 1981.Google Scholar
[GH1]Ghys, E., de la Harpe, P., Troyanov, M., Salem, E., Ballman, W., Haefliger, A. and Strebel, R.. Sur les Groupes Hyperboliques d' après Mikhael Gromov. Ghys, E. and de la Harpe, P., eds. Birkhäuser: Boston, 1990.Google Scholar
[Kec1]Kechris, A.. Countable sections for locally compact group actions. Ergod. Th. & Dynam. Sys. 12 (1992), 283295.Google Scholar
[Munk1]Munkres, J.. Topology, a First Course. Prentice-Hall: Englewood Cliffs, 1975.Google Scholar
[Zim1]Zimmer, R.. Strong rigidity for ergodic actions of semisimple Lie groups. Ann. Math. 112 (1980), 511529.Google Scholar
[Zim2]Zimmer, R.. Ergodic Theory and Semisimple Groups. Birkhäuser: Boston, 1984.Google Scholar
[Zim3]Zimmer, R.. Ergodic actions of semisimple groups and product relations. Ann. Math. 118 (1983), 919.Google Scholar
[Zim4]Zimmer, R.. Ergodic theory, semisimple Lie groups and foliations by manifolds of negative curvature. Publ. Math. IHES 55 (1982), 3762.Google Scholar