The non-hyperbolicity of irrational invariant curves for twist maps and all that follows
The non-hyperbolicity of irrational invariant curves for twist maps and all that follows
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扭曲映射的无理不变曲线的非双曲性以及以下所有内容
DOI:
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发表时间:
2014
期刊:
影响因子:
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通讯作者:
P. Berger
中科院分区:
文献类型:
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作者:
M. Arnaud;P. Berger
The key result of this article is key lemma: if a Jordan curve $gamma$ is invariant by a given C 1+$alpha$ -diffeomorphism f of a surface and if $gamma$ carries an ergodic hyperbolic probability $mu$, then $mu$ is supported on a periodic orbit. From this Lemma we deduce three new results for the C 1+$alpha$ symplectic twist maps f of the annulus: 1. if $gamma$ is a loop at the boundary of an instability zone such that f |$gamma$ has an irrational rotation number, then the convergence of any orbit to $gamma$ is slower than exponential; 2. if $mu$ is an invariant probability that is supported in an invariant curve $gamma$ with an irrational rotation number, then $gamma$ is C 1 $mu$-almost everywhere; 3. we prove a part of the so-called "Greene criterion", introduced by J. M. Greene in [16] in 1978 and never proved: assume that (pn qn) is a sequence of rational numbers converging to an irrational number $omega$; let (f k (x n)) 1$le$k$le$qn be a minimizing periodic orbit with rotation number pn qn and let us denote by R n its mean residue R n = |1/2 -- Tr(Df qn (x n))/4|