Abstract
In these lectures we discuss some topics concerning the relationship of ergodic theory, representation theory, and the structure of Lie groups and their discrete subgroups.
In studying the representation theory of groups, the assumption of compactness on the group essentially allows one to reduce to a finite dimensional situation, in which case one often can obtain complete information. For non-compact groups, of course, no such reduction is possible and the situation is much more complex. When studying general actions of groups, a somewhat similar situation arises. In the compact case every orbit will be closed, the space of orbits will have a reasonable structure, and one can often find nice (with respect to the action) neighborhoods of orbits. A large amount of information about actions of finite and compact groups has been obtained by topological methods. However, once again, if the compactness assumption on the group is dropped, one faces many additional problems. In particular, one can have orbits which are dense (for example, the irrational flow on the torus) and the orbit space may be so badly behaved as to have no continuous functions but constants. Furthermore, moving from a point to a nearby point may produce an orbit which doesn't follow closely to the original orbit. If one wishes to deal with actions in the non-compact case, this phenomenon of complicated orbit structure must be faced. For many actions, e.g., diffentiable actions on manifolds, there are natural measures that behave well with respect to the action. A significant part of ergodic theory is the study of group actions on measure spaces. In particular, ergodic theory aims to understand the phenomenon of bad orbit structure in the presence of a measure.
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References
L. Auslander, L. Green, F. Hahn, Flows on Homogeneous Spaces, Annals of Math. Studies, no.53, Princeton, 1963
L. Auslander, An Exposition of the Structure of Solvmanifolds, Bull. Amer. Math. Soc, 79(1973), 227–285.
A. Borel, Linear Algebraic Groups, Benjamin, New York, 1969.
A. Borel, Density Properties for Certain Subgroups of Semisimple Lie Groups Without Compact Factors, Annals of Math., 72(1960), 179–188.
A. Borel, Harish-Chandra, Arithmetic Subgroups of Algebraic Groups, Annals of Math., 75(1962), 485–535.
A. Borel, J .P. Serre, Theorèmes de Finitude en Cohomologie Galoisienne, Comm. Math. Helv., 39(1964), 111–164.
J. Brezin, CC. Moore, Flows on Homogeneous Spaces: A New Look, preprint.
A. Connes. J. Feldman, B̀. Weiss, Amenable equivalence relations are generated by a single transformation, preprint.
C. Delaroche, A Kirillov, Sur Les Relations Entre L'Espace Dual d'un Groupe et la Structure de ses Sous-Groupes Fermés, Seminaire Bourbaki, no.343, 1967/68.
H.A. Dye, On Groups of Measure Preserving Transformations, I, Amer. J. Math., 81(1959), 119–159.
H.A. Dye, On Groups of Measure Preserving Transformations, II, Amer. J. Math., 85(1963), 551–576.
E.G. Effros, Transformation Groups and C*-Algebras, Annals of Math., 81(1965), 38–55.
J. Feldman, P. Hahn, C .C. Moore, Orbit Structure and Countable Sections for Actions of Continuous Groups, Advances in Math., 28(1978), 186–230.
H. Freudenthal, Topologische Gruppen mit Genugend Vielen Fastperiodishen Funktionen, Annals of Math., 37(1936), 57–77.
H. Furstenberg, A Poisson Formula for Semi simple Lie Groups, Annals of Math., 77(1963), 335–383.
H. Furstenberg, The Structure of Distal Flows, Amer. J. Math., 85(1963), 477–515.
H. Furstenberg, Ergodic Behavior of Diagonal Measures and a Theorem of Szemeredi on Arithmetic Progressions, J. Analyse Math., 31(1977), 204–256.
F.P. Greenleaf, Invariant Means on Toplogical Groups, Van Nostrand, New York, 1969.
Y. Guivarc'h, Croissance Polynomiale et Periodes des Fonctions Harmonique, Bull. Math. Soc. France, 101(1973), 333–379
G. Hedlund, The Dynamics of Geodesic Flows, Bull. Amer. Math. Soc, 45(1939), 241–260.
E. Hopf, Statistik der Lösungen geodätischer probleme vom unstabilen typus, Math. Ann. 117(1940), 590–608.
R. Howe and C .C. Moore, Asymptotic Properties of Unitary Representations, J. Func, Anal .,32(1979), 72–96.
J.W. Jenkins, Growth of Connected Locally Compact Groups, J. Funct. Anal ., 12(1973), 113–127.
D. Kazhdan, Connection of the Dual Space of a Group with the Structure of its Closed Subgroups, Funct. Anal. Appl., 1(1967), 63–65.
W. Krieger, On Ergodic Flows and the Isomorphism of Factors, Math. Ann. 223(1976), 19–70.
G.W. Mackey, Ergodic Transformation Groups with a Pure Point Spectrum, Illinois J. Math., 8(1964), 593–600.
G.A. Margulis, Non-uniform lattices in Semi simple Algebraic Groups, in Lie Groups and their Representations, ed. I .M. Gelfand, Wiley, New York.
G.A. Margulis, Discrete Groups of Motions of Manifolds of Non-Positive Curvature, Amer. Math. Soc. Translations, 109(1977), 33–45.
G.A. Margulis, Arithmeticity of Irreducible Lattices in Semisimple Groups of Rank Greater than 1, Appendix to Russian Translation of M. Ragunathan, Discrete Subgroups of Lie Groups, Mir, Moscow, 1977(in Russian).
G.A. Margulis, Factor Groups of Discrete Subgroups, Soviet Math. Dokl. 19(1978), 1145–1149.
G.A. Margulis, Quotient Groups of Discrete Subgroups and Measure Theory, Funct. Anal. Appl., 12(1978), 295–305.
C.C. Moore, Ergodicity of Flows on Homogeneous Spaces, Amer. J. Math., 88(1966), 154–178.
C.C. Moore, Amenable Subgroups of Semisimple Groups and Proximal Flows, Israel J. Math., 34(1979), 121–138.
C.C. Moore and R.J. Zimmer, Groups Admitting Ergodic Actions with Generalized Discrete Spectrum, Invent. Math., 51(1979), 171–188.
G.D. Mostow, Quasi-Conformal Mappings in n - Space and the Rigidity -of Hyperbolic Space Forms, Publ . Math. I.H.E.S., (1967), 53–104.
G.D. Mostow, Strong Rigidity of Locally Symmetric Spaces, Annals of Math. Studies, no.78, Princeton Univ. Press, Princeton, N.J. 1973.
D. Ornstein and B. Weiss, to appear.
W. Parry, Zero Entropy of Distal and Related Transformations, in Topological Dynamics, eds. J. Auslander, W. Gottschalk, Benjamin, New York, 1968.
G. Prasad, Strong Rigidity of Q-rank 1 Lattices, Invent. Math., 21(1973), 255–286.
M. Ragunathan, Discrete Subgroups of Lie Groups, Springer-Verlag, New York, 1972.
A. Ramsay, Virtual Groups and Group Actions, Advances in Math., 6(1971), 253–322.
A. Selberg, On Discontinuous Groups in Higher Dimensional Symmetric Spaces, Int. Colloquium on Function Theory, Tata Institute, Bombay, 1960.
T. Sherman, A Weight Theory for Unitary Representations, Canadian J. Math., 18(1966), 159–168.
C. Sutherland, Orbit Equivalence: Lectures on Kriegers Theorem, University of Oslo Lecture Notes.
V.S. Varadarajan, Geometry of Quantum Theory, vol. II., Van Nostrand, Princeton, N.J. 1970.
S.P. Wang, On Isolated Points in the Dual Spaces of Locally Compact Groups, Math. Ann., 218(1975), 19–34.
R.J. Zimmer, Extensions of Ergodic Group Actions, Illinois J. Math., 20(1976), 373–409.
R.J. Zimmer, Ergodic Actions with Generalized Discrete Spectrum, Illinois J. Math., 20(1976), 555–588.
R.J. Zimmer, Orbit Spaces of Unitary Representations, Ergodic Theory, and Simple Lie Groups, Annals of Math., 106(1977), 573–588.
R.J. Zimmer, Uniform Subgroups and Ergodic Actions of Exponential Lie Groups, Pac. J. Math., 78(1978), 267–272.
R.J. Zimmer, Amenable Ergodic Group Actions and an Application to Poisson Boundaries of Random Walks, J. Funct. Anal., 27(1978), 350–372.
R.J. Zimmer, Induced and Amenable Ergodic Actions of Lie Groups, Ann. Sci. Ec. Norm. Sup., 11(1978), 407–428.
R.J. Zimmer, Algebraic Topology of Ergodic Lie Group Action and Measurable Foliations, preprint.
R.J. Zimmer, An Algebraic Group Associated to an Ergodic Diffeomorphism, Comp. Math., to appear.
R.J. Zimmer, Strong Rigidity for Ergodic Actions of Semisimple Lie Groups, Annals of Math., to appear.
R.J. Zimmer, Orbit Equivalence and Rigidity of Ergodic Actions of Lie Groups, preprint.
R.J. Zimmer, On the Cohomology of Ergodic Actions of Semisimple lie Groups and Discrete subgroups, Amer. J. Math., to appear.
R.J. Zimmer, On the Mostow Rigidity Theorem and Measurable Foliations by Hyperbolic Space, preprint.
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Zimmer, R.J. (2010). Ergodic Theory, Group Representations, and Rigidity. In: Talamanca, A.F. (eds) Harmonic Analysis and Group Representation. C.I.M.E. Summer Schools, vol 82. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-11117-4_7
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