Escape quartered theorem and the connectivity of the Julia sets of a family of rational maps

Youming Wang; Fei Yang; Song Zhang; Liangwen Liao

doi:10.3934/dcds.2019211

Article Contents

2019, Volume 39, Issue 9: 5185-5206. Doi: 10.3934/dcds.2019211

This issue Previous Article Nonhydrostatic Pollard-like internal geophysical waves Next Article On attainability of Moser-Trudinger inequality with logarithmic weights in higher dimensions

Escape quartered theorem and the connectivity of the Julia sets of a family of rational maps

1.
Department of Mathematics, Nanjing University, Nanjing 210093, China
2.
Department of Applied Mathematics, Hunan Agricultural University, Changsha 410128, China
3.
Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190, China

^* Corresponding author: Youming Wang
^* Corresponding author: Youming Wang

Received: July 31, 2018

Revised: March 31, 2019

Published: May 2019

This work is supported by the NSFC (grant Nos. 11671092, 11671191, 11871208), by the Scientific Research Foundation of Hunan Provincial Education Department (grant No. 16C0763), by Natural Science Foundation of Hunan Province (grant No. 2018JJ2159) and by the Fundamental Research Funds for the Central Universities (grant Nos. 0203-14380022 and 0203-14380025)

Abstract Full Text(HTML) Figure(4) Related Papers Cited by

Abstract

In this paper, we investigate the dynamics of the following family of rational maps

$ \begin{equation*} f_{\lambda}(z) = \frac{z^{2n} - \lambda^{3n+1}}{z^n(z^{2n} - \lambda^{n - 1})} \end{equation*} $

with one parameter $ \lambda \in \mathbb{C}^* - \{\lambda: \lambda^{2n + 2} = 1\} $, where $ n\geq 2 $. This family of rational maps is viewed as a singular perturbation of the bi-critical map $ P_{-n}(z) = z^{-n} $ if $ \lambda \neq 0 $ is small. It is proved that the Julia set $ J(f_\lambda) $ is either a quasicircle, a Cantor set of circles, a Sierpiński carpet or a degenerate Sierpiński carpet provided the free critical orbits of $ f_\lambda $ are attracted by the super-attracting cycle $ 0\leftrightarrow\infty $. Furthermore, we prove that there exists suitable $ \lambda $ such that $ J(f_\lambda) $ is a Cantor set of circles but the dynamics of $ f_{\lambda} $ on $ J(f_{\lambda}) $ is not topologically conjugate to that of any known rational maps with only one or two free critical orbits (including McMullen maps and the generalized McMullen maps). The connectivity of $ J(f_{\lambda}) $ is also proved if the free critical orbits are not attracted by the cycle $ 0\leftrightarrow\infty $. Finally we give an estimate of the Hausdorff dimension of the Julia set of $ f_\lambda $ in some special cases.

Keywords:

Mathematics Subject Classification: Primary: 37F45; Secondary: 37F10, 37F25.

Citation:

Full Text(HTML)

Figure 1. The Julia sets of $ f_\lambda $ for different $ \lambda $'s when $ n = 4 $. Top left: $ \lambda = 0.8 + 0.3 \rm{i} $ and $ J(f_\lambda) $ is a quasicircle; Top right: $ \lambda = 0.4 $ and $ J(f_\lambda) $ is a Cantor set of circles; Bottom left: $ \lambda = 0.7 $ and $ J(f_\lambda) $ is a Sierpiński carpet; Bottom right: $ \lambda = 0.92 + 0.01 \rm{i} $ and $ J(f_\lambda) $ is a degenerate Sierpiński carpet

Download: Full-size image PowerPoint slide

Figure 2. The non-escaping loci of $ f_\lambda $, where $ n = 3 $ and $ 4 $. Left: $ n = 3 $, the McMullen domain does not exist and the Julia set $ J(f_\lambda) $ cannot be a Cantor set of circles; Right: $ n = 4 $, there is a punctured domain centered at origin which corresponds to the McMullen domain (the big white part in the center)

Download: Full-size image PowerPoint slide

Figure 3. The above and below pictures illustrate the mapping relations of $ h_\lambda $ (see (1)) and $ f_\lambda $ respectively when $ D_0 $ contains one of the free critical values but contains no free critical points. One can observe clearly that $ f_{\lambda} $ and $ h_{\lambda} $ are not topologically conjugate on their corresponding Julia sets

Download: Full-size image PowerPoint slide

Figure 4. The Julia sets of $ f_\lambda $ with $ n = 4 $, $ \lambda = 0.4 $ and $ F(z) = z^3 + 0.01/z^3 $. Both of them are Cantor circles. But $ f_{\lambda} $ and $ F $ are not topologically conjugate on their corresponding Julia sets

Download: Full-size image PowerPoint slide

Related Papers

Cited by

References

[1]	A. F. Beardon, Iteration of Rational Functions, Grad. Texts in Math., 132, Springer-Verlag, New York, 1991. doi: 10.1007/978-1-4612-4422-6.
[2]	M. Bonk, M. Lyubich and S. Merenkov, Quasisymmetries of Sierpiński carpet Julia sets, Adv. Math., 301 (2016), 383-422. doi: 10.1016/j.aim.2016.06.007.
[3]	L. Carleson and T. W. Gamelin, Complex Dynamics, Universitext: Tracts in Mathematics, Springer, New York, N.Y., 1993. doi: 10.1007/978-1-4612-4364-9.
[4]	R. L. Devaney, N. Fagella, A. Garijo and X. Jarque, Sierpiński curve Julia sets for quadratic rational maps, Ann. Acad. Sci. Fenn. Math., 39 (2014), 3-22. doi: 10.5186/aasfm.2014.3903.
[5]	R. L. Devaney, D. Look and D. Uminsky, The escape trichotomy for singularly perturbed rational maps, Indiana. Univ. Math. J., 54 (2005), 1621-1634. doi: 10.1512/iumj.2005.54.2615.
[6]	R. L. Devaney, Singular perturbations of complex polynomials, Bull. Amer. Math. Soc., 50 (2013), 391-429. doi: 10.1090/S0273-0979-2013-01410-1.
[7]	R. L. Devaney and E. D. Russell, Connectivity of Julia sets for singularly perturbed rational maps, Chaos, CNN, Memristors and Beyond, World Scientific, 2013,239–245. doi: 10.1142/9789814434805_0018.
[8]	A. Douady and J. H. Hubbard, On the dynamics of polynomial-like mappings, Ann. Sci. École. Norm. Sup., 18 (1985), 287–343. doi: 10.24033/asens.1491.
[9]	J. Fu and F. Yang, On the dynamics of a family of singularly perturbed rational maps, J. Math. Anal. Appl., 424 (2015), 104-121. doi: 10.1016/j.jmaa.2014.10.090.
[10]	J. Fu and Y. Zhang, Connectivity of the Julia sets of singularly perturbed rational maps, Proc. Indian Acad. Sci. Math. Sci., 129 (2019), 32. doi: 10.1007/s12044-019-0478-8.
[11]	Y. Fu and F. Yang, Area and Hausdorff dimension of Sierpiński carpet Julia sets, to appear in Math. Z., (2019). arXiv: 1812.03016. doi: 10.1007/s00209-019-02319-4.
[12]	A. Garijo and S. Godillon, On McMullen-like mappings, J. Fractal Geom., 2 (2015), 249-279. doi: 10.4171/JFG/21.
[13]	A. Garijo, S. M. Marotta and E. D. Russell, Singular perturbations in the quadratic family with multiple poles, J. Difference Equ. Appl., 19 (2013), 124-145. doi: 10.1080/10236198.2011.630668.
[14]	P. Haïsinsky and K. Pilgrim, Quasisymmetrically inequivalent hyperbolic Julia sets, Rev. Mat. Iberoam., 28 (2012), 1025-1034. doi: 10.4171/RMI/701.
[15]	J. Hu, O. Muzician and Y. Xiao, Dynamics of regularly ramified rational maps: Ⅰ. Julia sets of maps in one-parameter families, Discrete Contin. Dyn. Syst., 38 (2018), 3189-3221. doi: 10.3934/dcds.2018139.
[16]	J. Hu and Y. Xiao, No Herman rings for regularly ramified rational maps, Proc. Amer. Math. Soc., 147 (2019), 1587-1596. doi: 10.1090/proc/14347.
[17]	C. T. McMullen, Automorphisms of rational maps, In Holomorphic functions and moduli I, Mathematical Sciences Research Institute Publications, Springer-Verlag, New York, NY, 10 (1988), 31–60. doi: 10.1007/978-1-4613-9602-4_3.
[18]	J. Milnor, Dynamics in one Complex Variable, Third Edition, Annals of Mathematics Studies, 160, Princeton Univ. Press, Princeton, NJ, 2006.
[19]	M. Pilgrim and L. Tan, Rational maps with disconnected Julia set, in Géométrie Complexe Et Systèmes Dynamiques, Astérisque, 261 (2000), 349–384.
[20]	F. Przytycki, On the hyperbolic Hausdorff dimension of the boundary of a basin of attraction for a holomorphic map and of quasirepellers, Bull. Pol. Acad. Sci. Math., 54 (2006), 41-52. doi: 10.4064/ba54-1-4.
[21]	W. Qiu, X. Wang and Y. Yin, Dynamics of McMullen maps, Adv. Math., 229 (2012), 2525-2577. doi: 10.1016/j.aim.2011.12.026.
[22]	W. Qiu and F. Yang, Hausdorff dimension and quasi-symmetric uniformization of Cantor circle Julia sets, arXiv: 1811.10042, 2018.
[23]	W. Qiu, F. Yang and Y. Yin, Rational maps whose Julia sets are Cantor circles, Ergodic Theory Dynam. Systems, 35 (2015), 499-529. doi: 10.1017/etds.2013.53.
[24]	W. Qiu, F. Yang and Y. Yin, Quasisymmetric geometry of the Cantor circles as the Julia sets of rational maps, Discrete Contin. Dynam. Sys., 36 (2016), 3375-3416. doi: 10.3934/dcds.2016.36.3375.
[25]	W. Qiu, F. Yang and J. Zeng, Quasisymmetric geometry of the carpet Julia sets, Fund. Math., 244 (2019), 73-107. doi: 10.4064/fm494-12-2017.
[26]	D. Sullivan, Conformal dynamical systems, Geometric Dynamics (Rio de Janeiro, 1981), 725–752, Lecture Notes in Math., 1007, Springer, Berlin, 1983. doi: 10.1007/BFb0061443.
[27]	Y. Wang and F. Yang, Julia sets as buried Julia components, arXiv: 1707.04852, 2017.
[28]	G. T. Whyburn, Topological characterization of the Sierpiński curves, Fund. Math., 45 (1958), 320-324. doi: 10.4064/fm-45-1-320-324.
[29]	Y. Xiao and W. Qiu, The rational maps $F_\lambda(z)=z^m+\lambda/z^d$ have no Herman rings, Proc. Indian Acad. Sci. Math. Sci., 120 (2010), 403-407. doi: 10.1007/s12044-010-0044-x.
[30]	Y. Xiao, W. Qiu and Y. Yin, On the dynamics of generalized McMullen maps, Ergod. Th. & Dynam. Sys., 34 (2014), 2093-2112. doi: 10.1017/etds.2013.21.
[31]	Y. Xiao and F. Yang, Singular perturbations with multiple poles of the simple polynomials, Qual. Theory Dyn. Syst., 16 (2017), 731-747. doi: 10.1007/s12346-016-0205-0.
[32]	Y. Xiao and F. Yang, Singular perturbations of unicritical polynomials with two parameters, Ergod. Th. Dynam. Sys., 37 (2017), 1997-2016. doi: 10.1017/etds.2015.114.
[33]	F. Yang, Rational maps without Herman rings, Proc. Amer. Math. Sci, 145 (2017), 1649-1659. doi: 10.1090/proc/13336.
[34]	F. Yang, A criterion to generate carpet Julia sets, Proc. Amer. Math. Soc., 146 (2018), 2129-2141. doi: 10.1090/proc/13924.