Let $ g $ be a smooth expanding map of degree $ D $ which maps a circle to itself, where $ D $ is a natural number greater than $ 1 $. It is known that the Lyapunov exponent of $ g $ with respect to the unique invariant measure that is absolutely continuous with respect to the Lebesgue measure is positive and less than or equal to $ \log D $ which, in addition, is less than or equal to the Lyapunov exponent of $ g $ with respect to the measure of maximal entropy. Moreover, the equalities can only occur simultaneously. We show that these are the only restrictions on the Lyapunov exponents considered above for smooth expanding maps of degree $ D $ on a circle.
Citation: |
[1] |
J. Bochi, A. Katok and F. Rodrigues Hertz, Flexibility of Lyapunov exponents among conservative diffeomorphisms, preprint.
![]() |
[2] |
A. Boyarsky and M. Scarowsky, On a class of transformations which have unique absolutely continuous invariant measures, Trans. Amer. Math. Soc., 255 (1979), 243-262.
doi: 10.1090/S0002-9947-1979-0542879-2.![]() ![]() ![]() |
[3] |
A. Erchenko and A. Katok, Flexibility of entropies for surfaces of negative curvature, to appear in Israel J. Math., arXiv:1710.00079.
![]() |
[4] |
A. Góra and A. Boyarsky, Compactness of invariant densities for families of expanding, piecewise monotonic transformations, Canad. J. Math., 41 (1989), 855-869.
doi: 10.4153/CJM-1989-039-8.![]() ![]() ![]() |
[5] |
A. Katok and B. Hasselblatt, Introduction to the Modern Theory of Dynamical Systems, Cambridge University Press, Cambridge, 1995.
doi: 10.1017/CBO9780511809187.![]() ![]() ![]() |
[6] |
A. Lasota and J. A. Yorke, On the existence of invariant measures for piecewise monotonic transformations, Trans. Amer. Math. Soc., 186 (1973), 481-488.
doi: 10.1090/S0002-9947-1973-0335758-1.![]() ![]() ![]() |
[7] |
M. Qian, J.-S. Xie and S. Zhu, Smooth Ergodic Theory for Endomorphisms, Springer-Verlag, Berlin, 2009.
doi: 10.1007/978-3-642-01954-8.![]() ![]() ![]() |
[8] |
D. Ruelle, An inequality for the entropy of differentiable maps, Bol. Soc. Brasil. Mat., 9 (1978), 83-87.
doi: 10.1007/BF02584795.![]() ![]() ![]() |
[9] |
P. Walters, Invariant measures and equilibrium states for some mappings which expand distances, Trans. Amer. Math. Soc., 236 (1978), 121-153.
doi: 10.1090/S0002-9947-1978-0466493-1.![]() ![]() ![]() |
A representative of the SUSD-circle maps of degree