Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-20T08:34:11.687Z Has data issue: false hasContentIssue false

Spectral measure of the Thue–Morse sequence and the dynamical system and random walk related to it

Published online by Cambridge University Press:  06 February 2015

LI PENG
Affiliation:
Department of Mathematics, Huazhong University of Science and Technology, Wuhan 430074, PR China email lpeng@hust.edu.cn
TETURO KAMAE
Affiliation:
Advanced Mathematical Institute, Osaka City University, 558-8585, Japan email kamae@apost.plala.or.jp

Abstract

Let $1,-1,-1,1,-1,1,1,-1,-1,1,1,\ldots$ be the $\{-1,1\}$-valued Thue–Morse sequence. Its correlation dimension is $D_{2}$, satisfying

$$\begin{eqnarray}\mathop{\sum }_{k=0}^{K-1}|{\it\gamma}(k)|^{2}\asymp K^{1-D_{2}}\end{eqnarray}$$
in the sense that the ratio between the left- and right-hand sides is bounded away from 0 and $\infty$ as $K\rightarrow \infty$, where ${\it\gamma}$ is the correlation function; its value is known [Zaks, Pikovsky and Kurths. On the correlation dimension of the spectral measure for the Thue–Morse sequence. J. Stat. Phys.88(5/6) (1997), 1387–1392] to be
$$\begin{eqnarray}D_{2}=1-\log \frac{1+\sqrt{17}}{4}\bigg/\log 2=0.64298\ldots .\end{eqnarray}$$
Under its spectral measure ${\it\mu}$ on $[0,1)$, consider the transformation $T$ with $Tx=2x$ ($\text{mod}~1$). It is shown to be of Kolmogorov type having entropy at least $D_{2}\log 2$. Moreover, a random walk is defined by $T^{-1}$ which has the transition probability
$$\begin{eqnarray}P_{1}((1/2)x+(1/2)j\mid x)=(1/2)(1-\cos ({\it\pi}(x+j)))\quad (j=0,1).\end{eqnarray}$$
It is proved that this random walk is mixing and ${\it\mu}$ is the unique stationary measure. Moreover,
$$\begin{eqnarray}\lim _{N\rightarrow \infty }\int P_{N}((x-{\it\varepsilon},x+{\it\varepsilon})|x)\,d{\it\mu}(x)\asymp {\it\varepsilon}^{D_{2}}\quad (\text{as}~{\it\varepsilon}\rightarrow 0),\end{eqnarray}$$
where $P_{N}(\cdot \mid \cdot )$ is the $N$-step transition probability.

Type
Research Article
Copyright
© Cambridge University Press, 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Cao, Li, Xi, Lifeng and Zhang, Yiping. L p estimate of convolution transformation of singular measure by approximate identity. Nonlinear Anal. 94 (2014), 148155.Google Scholar
Coquet, J., Kamae, T. and Mendès, M.. France, La mesure spectrale de certaines suites arithmétiques. Bull. Soc. Math. France 105 (1977), 369387.Google Scholar
Kakutani, S.. Ergodic theory of shift transformations. Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability. Eds. LeCam, L. and Neyman, J.. University of California Press, Berkeley, 1967.Google Scholar
Mahler, K.. On the translation properties of a simple class of arithmetical functions. J. Mat. Phys. 6 (1927), 158163.Google Scholar
Petersen, K.. Ergodic Theory. Cambridge University Press, Cambridge, 1983.CrossRefGoogle Scholar
Queffélec, M.. Substitution Dynamical Systems—Spectral Analysis (Lecture Notes in Mathematics, 1294). Springer, Berlin, 1987.CrossRefGoogle Scholar
Wen, Z. and Zhang, Y.. Some boundary fractal properties of the convolution transform of measures by an approximate identity. Acta Math. Sin. (1999), 207–214; English Series 15 No. 2.Google Scholar
Zaks, M. A., Pikovsky, A. S. and Kurths, J.. On the correlation dimension of the spectral measure for the Thue–Morse sequence. J. Stat. Phys. 88(5/6) (1997), 13871392.Google Scholar