Abstract
LetT α be the translationx↦x+α (mod 1) of [0, 1), α irrational. LetT be the Lebesgue measure-preserving automorphism ofX=[0, 3/2) defined byTx = x + 1 forx∈[0, 1/2),Tx=T α(x−1) forx∈[1,3/2) andTx = T α x forx∈[1/2, 1), i.e.T isT α with a tower of height one built over [0, 1/2). If α is poorly approximable by rationals (there does not exist {p n /q n } with |α−p n /q n |=o(q n −2)) and λ is a measure onX k all of whose one-dimensional marginals are Lebesgue and which is ⊗ k i − 1 T 1 invariant and ergodic (l>0) then λ is a product of off-diagonal measures. This property suffices for many purposes of counterexample construction. A connection is established with the POD (proximal orbit dense) condition in topological dynamics.
Similar content being viewed by others
References
J. Aaronson and M. Keane,The visits to zero of some deterministic random walks, preprint.
R. V. Chacón,Transformations having continuous spectrum, J. Math. Mech.16 (1966), 399–415.
R. V. Chacón,Weakly mixing transformations which are not strongly mixing, Proc. Am. Math. Soc.22 (1969), 559–562.
H. Furstenberg, H Keynes and L. Shapiro,Prime flows in topological dynamics, Isr. J. Math.14 (1973), 26–38.
A. del Junco,A simple measure-preserving transformation with trivial centralizer, Pac. J. Math.79 (1978), 357–362.
A. del Junco and D. Rudolph,Universally disjoint measure-preserving systems, to appear.
A. del Junco, M. Rahe and L. Swanson,Chacón's automorphism has minimal self-joinings, J. Analyse Math.37 (1980), 276–284.
S. Kakutani,Examples of ergodic measure-preserving transformations which are weakly mixing but not strongly mixing, Springer Lecture Notes in Math.318 (1973), 143–149.
A. B. Katok, Ya. G. Sinai and A. M. Stepin,Theory of dynamical systems and general transformation groups with invariant measure, J. Sov. Math.7 (1977), 974–1065.
M. Keane,Irrational rotations and quasi-ergodic measures, Publ. des Séminaires de Math. (Fasc. I Prob.), Rennes, 1970–71.
D. S. Ornstein,On the root problem in ergodic theory, Proc. Sixth Berkeley Symp. Math. Stat. Prob. Vol. II, University of California Press, 1967, pp. 347–356.
D. Rudolph,An example of a measure-preserving map with minimal self-joinings, and applications, J. Analyse Math.35 (1979), 97–122.
W. Weech,Strict ergodicity in zero-dimensional dynamical systems and the Kronecker-Weyl theorem mod 2, Trans. Am. Math. Soc.140 (1969), 1–33.
W. Veech,Well distributed sequences of integers, Trans. Am. Math. Soc.161 (1971), 63–70.
Author information
Authors and Affiliations
Additional information
Research supported in part by NSF contract MCS-8003038.
Rights and permissions
About this article
Cite this article
del Junco, A. A family of counterexamples in ergodic theory. Israel J. Math. 44, 160–188 (1983). https://doi.org/10.1007/BF02760618
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02760618