Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-16T17:01:45.719Z Has data issue: false hasContentIssue false

Automorphisms of solenoids and p-adic entropy*

Published online by Cambridge University Press:  19 September 2008

D. A. Lind
Affiliation:
Department of Mathematics, University of Washington, Seattle, WA 98195, USA
T. Ward
Affiliation:
Mathematics Institute, University of Warwick, Coventry CV4 7AL, England
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We show that a full solenoid is locally the product of a euclidean component and p-adic components for each rational prime p. An automorphism of a solenoid preserves these components, and its topological entropy is shown to be the sum of the euclidean and p-adic contributions. The p-adic entropy of the corresponding rational matrix is computed using its p-adic eigenvalues, and this is used to recover Yuzvinskii's calculation of entropy for solenoidal automorphisms. The proofs apply Bowen's investigation of entropy for uniformly continuous transformations to linear maps over the adele ring of the rationals.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1988

References

REFERENCES

[Ab]Abromov, L. M.. The entropy of an automorphism of a solenoidal group. Teor. Verojalnost. i Primenen. 4 (1959), 249254 (Russian).Google Scholar
Eng. transl. Theory of Prob. and Applic. IV (1959), 231236. MR 22 #8103.Google Scholar
[Ar]Arov, D. Z.. Calculation of entropy for a class of group endomorphisms. Zap. Meh.-Mat. Fak. Har'kov. Gos. Univ. i Har'kov. Mat. Obšč. 30 (1964), 4869 (Russian). MR 35 #4368.Google Scholar
[Be]Berg, K.. Convolution of invariant measure, maximal entropy. Math. Systems Theory 3 (1969), 46150.CrossRefGoogle Scholar
[B]Bowen, R.. Entropy for group endomorphisms and homogeneous spaces. Trans. Amer. Math. Soc. 153 (1971), 401414.CrossRefGoogle Scholar
Erratum, 181 (1973), 509510.Google Scholar
[G]Genis, A. L.. Metric properties of endomorphisms of an r-dimensional torus. Dokl. Akad. Nauk SSSR 138 (1961), 991993 (Russian).Google Scholar
Engl. transl. Soviet Math. Dokl. 2 (1961), 750752. MR 34 #2766.Google Scholar
[H]Halmos, P. R.. On automorphisms of compact groups. Bull. Amer. Math. Soc. 49 (1943), 619624.CrossRefGoogle Scholar
[K]Koblitz, N.. p-adic Numbers, p-adic Analysis, and Zeta Functions. Springer: New York, 1977.CrossRefGoogle Scholar
[Lan]Lang, S.. Fundamentals of Diophantine Geometry. Springer: New York, 1983.CrossRefGoogle Scholar
[La]Lawton, W.. The structure of compact connected groups which admit an expansive automorphism. Springer Lect. Notes in Math. 318 (1973), 182196.CrossRefGoogle Scholar
[L1]Lind, D.. p-adic entropy (abstract). L. M. S. Durham Conference on Ergodic Theory Abstracts.University of Warwick, 1980.Google Scholar
[L2]Lind, D.. Ergodic group automorphisms are exponentially recurrent. Israel J. Math. 41 (1982), 313320.CrossRefGoogle Scholar
[P]Peters, J.. Entropy on discrete abelian groups. Advances in Math. 33 (1979), 113.CrossRefGoogle Scholar
[R]Rohlin, V. A.. Exact endomorphisms of a Lebesgue space. Izv. Akad. Nauk SSSR, Ser. Mat. 25 (1961), 499530 (Russian).Google Scholar
Engl. transl. Amer. Math. Soc. Transl. (2) 39 (1964), 136. MR 26 #1423.Google Scholar
[S]Sinaǐ, Ja. G.. On the concept of entropy of a dynamic system. Dokl. Akad. Nauk SSSR 124 (1959), 768771 (Russian). MR 21 #2036a.Google Scholar
[Wa]Walters, P.. An Introduction to Ergodic Theory. Springer: New York, 1982.CrossRefGoogle Scholar
[W]Ward, T.. Entropy of automorphisms of the solenoid. M.Sc. Dissertation, Warwick, 1986.Google Scholar
[We]Weil, A.. Basic Number Theory 3rd ed., Springer: New York, 1974.CrossRefGoogle Scholar
[Y]Yuzvinskii, S. A.. Computing the entropy of a group endomorphism. Sibirsk. Mat. Ž. 8 (1967), 230239 (Russian).Google Scholar
Eng. transl. Siberian Math. J. 8 (1968), 172178.Google Scholar