Asymptotic distributions of preimages for endomorphisms
Asymptotic distributions of preimages for endomorphisms
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自同态原像的渐近分布
DOI:
10.1017/s0143385710000155
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发表时间:
2010
影响因子:
0.9
通讯作者:
Eugen Mihailescu
中科院分区:
文献类型:
--
作者:
Eugen Mihailescu
Abstract Attractors for hyperbolic diffeomorphisms are known to possess unique Sinai–Ruelle–Bowen measures with interesting properties. In this paper we investigate the case of non-invertible maps (endomorphisms) which have repellers Λ. We work with preimages of points in a neighbourhood of the repeller (assumed to be non-expanding); the situation here is different than the one for diffeomorphisms or positive iterates of endomorphisms. We give two methods to obtain invariant measures from local inverse iterates. We show that if Λ is a hyperbolic s-conformal repeller for f, not necessarily expanding, and if f is d-to-1 on Λ then for Lebesgue almost every x in the repelling basin of Λ there are histories of x asymptotically distributed like the equilibrium measure μs of the Hölder continuous potential Φs, with Φs (y):=log ∣Dfs (y)∣ for y∈Λ. The measure μs plays the role of an inverse Sinai–Ruelle–Bowen measure on the non-invertible repeller. We prove also that there exists a set A⊂Wuε(Λ) with λ(A)=λ(Wuε(Λ)) (where λ(⋅) is the Lebesgue measure) such that for any z∈A and any real continuous function g, \[ {\int }_{\!\!W^u_\varepsilon (\Lambda )} |\mu _n^z(g) - \mu _s(g)| \,d\lambda (z) \mathop {\to }\limits _n 0, \] with \[\mu _n^z := \frac 1n \sum _{k=1}^n \frac {\sum _{y \in f_\Lambda ^{-k} z} \delta _y}{d^k}. \] In particular, we obtain the asymptotic distribution of preimages of Lebesgue almost all points for a class of hyperbolic toral endomorphisms on ?m,m≥2 .