On Hausdorff dimension of some Cantor attractors

Multi-Model Cantor Sets

In this paper we define a new class of metric spaces, called multi-model Cantor sets. We compute the Hausdorff dimension and show that the Hausdorff measure of a multi-model Cantor set is finite and non-zero. We then show that a bilipschitz map from one multi-model Cantor set to another has constant Radon-Nikodym derivative on some clopen. We use this to obtain an invariant up to bilipschitz homeomorphism.

Hausdorff and harmonic measures on non-homogeneous Cantor sets

We consider (not self-similar) Cantor sets defined by a sequence of piecewise linear functions. We prove that the dimension of the harmonic measure on such a set is strictly smaller than its Hausdorff dimension. Some Hausdorff measure estimates for these sets are also provided.

Cantor Julia sets with Hausdorff dimension two

We prove the existence of Cantor Julia sets with Hausdorff dimension two. In particular, such examples can be found in cubic polynomials. The proof is based on the characterization of the parameter spaces and dynamical planes of cubic polynomials by Branner-Hubbard, and the parabolic bifurcation theory developed by Shishikura in 1990s.

Hausdorff Dimension of Cantor Series

In 1996 Y. Kifer obtained a variational formula for the Hausdorff dimension of the set of points for which the frequencies of the digits in the Cantor series expansion is given. In this note we present a slightly different approach to this problem that allow us to solve the variational problem of Kifer's formula.

Hausdorff--Lebesgue dimension of attractors

In the present paper the classical ideas of Hausdorff and Lebesgue are combined and the Hausdorff--Lebesgue measure is introduced. This makes it possible to obtain new results in chaotic dynamics.

Invariant space under Hénon renormalization : Intrinsic geometry of Cantor attractor

Three dimensional Hńon-like map $$ F(x,y,z) = (f(x) - ε(x,y,z),\ x,\ δ(x,y,z)) $$ is defined on the cubic box $ B $. An invariant space under renormalization would appear only in higher dimension. Consider renormalizable maps each of which satisfies the condition $$ \partial_y δ\circ F(x,y,z) + \partial_z δ\circ F(x,y,z) \cdot \partial_x δ(x,y,z) \equiv 0 $$ for $ (x,y,z) \in B $. Denote the set of maps satisfying the above condition be $ \mathcal N $. Then the set $ \mathcal N \cap \mathcal I(\bar ε) $ is invariant under the renormalization operator where $ \mathcal I(\bar ε) $ is the set of …

Quasisymmetric uniformization and Hausdorff dimensions of Cantor circle Julia sets

For Cantor circle Julia sets of hyperbolic rational maps, we prove that they are quasisymmetrically equivalent to standard Cantor circles (i.e., connected components are round circles). This gives a quasisymmetric uniformization of all Cantor circle Julia sets of hyperbolic rational maps. By analyzing the combinatorial information of the rational maps whose Julia sets are Cantor circles, we give a computational formula of the number of the Cantor circle hyperbolic components in the moduli space of rational maps for any fixed degree. We calculate the Hausdorff dimensions of the Julia sets which…

On the Hausdorff Dimension of Piecewise Hyperbolic Attractors

We study non-invertible piecewise hyperbolic maps in the plane. The Hausdorff dimension of the attractor is calculated in terms of the Lyapunov exponents, provided that the map satisfies a transversality condition. Explicit examples of maps for which this condition holds are given.

The Hausdorff dimension of the set of dissipative points for a Cantor-like model set for singly cusped parabolic dynamics

In this paper we introduce and study a certain intricate Cantor-like set $C$ contained in unit interval. Our main result is to show that the set $C$ itself, as well as the set of dissipative points within $C$, both have Hausdorff dimension equal to 1. The proof uses the transience of a certain non-symmetric Cauchy-type random walk.

Hausdorff Dimension, Lagrange and Markov Dynamical Spectra for Geometric Lorenz Attractors

In this paper, we show that geometric Lorenz attractors have Hausdorff dimension strictly greater than $2$. We use this result to show that for a "large" set of real functions the Lagrange and Markov Dynamical spectrum associated to these attractors has persistently non-empty interior.

Cantor集的笛卡尔积的Hausdorff测度

Hausdorff measure of cartesian product of Cantor sets

本文研究了$1/3$ Cantor集$d$重笛卡尔积的Hausdorff测度界限，通过应用强开集条件定理并推广已有工作，计算了几个小整数$d$下更严格的上下界。

Continuous images of Cantor's ternary set

The Hausdorff-Alexandroff Theorem states that any compact metric space is the continuous image of Cantor's ternary set $C$. It is well known that there are compact Hausdorff spaces of cardinality equal to that of $C$ that are not continuous images of Cantor's ternary set. On the other hand, every compact countably infinite Hausdorff space is a continuous image of $C$. Here we present a compact countably infinite non-Hausdorff space which is not the continuous image of Cantor's ternary set.

Hausdorff dimension of Cantor intersections and robust heterodimensional cycles for heterochaos horseshoe maps

As a model to provide a hands-on, elementary understanding of chaotic dynamics in dimension three, we introduce a $C^2$-open set of diffeomorphisms of $\mathbb R^3$ having two horseshoes with different dimensions of instability. We prove that: the unstable set of one horseshoe and the stable set of the other are of Hausdorff dimension nearly $2$ whose cross sections are Cantor sets; the intersection of the unstable and stable sets contains a fractal set of Hausdorff dimension nearly $1$. As a corollary we detect $C^2$-robust heterodimensional cycles. Our proof employs the theory of normally hy…

Dimension rigidity for cookie-cutter Cantor sets

We show that two cookie-cutter Cantor sets with the same symbolic coding are differentiably equivalent if and only if their Hausdorff dimensions are equal.

论滑动Shilnikov不变集的Hausdorff维数与Cantor集结构

On the Hausdorff dimension and Cantor set structure of sliding Shilnikov invariant sets

本文对Filippov系统中Shilnikov滑动连接的首回归映射进行局部分析，揭示了其共形迭代函数系统结构，证明了其局部不变集的闭包为Cantor集，并精确估计了其Hausdorff维数严格介于0和1之间且Lebesgue测度为0。

A combinatorial proof of Marstrand's Theorem for products of regular Cantor sets

In 1954 Marstrand proved that if K is a subset of R^2 with Hausdorff dimension greater than 1, then its one-dimensional projection has positive Lebesgue measure for almost-all directions. In this article, we give a combinatorial proof of this theorem when K is the product of regular Cantor sets of class C^{1+a}, a>0, for which the sum of their Hausdorff dimension is greater than 1.

The Semicontinuity of Attractors for Closed Relations on Compact Hausdorff Spaces

We show that attractors are semicontinuous for closed relations on compact Hausdorff spaces. Semicontinuity is what guarantees that small changes to a system do not result in massive growth of certain features, notably attractors. That is, there is a certain preservation of structure. When it comes to flows, semiflows, and maps, it is well established that attractors are semicontinuous. In [2], relations were established as a way to generalize maps, and a formal definition of attractors was established. Relations (in the dynamical systems sense) represent discrete time systems, which may lack …

关于康托集交集与随机矩阵乘积的交集

On the intersection of Cantor sets and products of random matrices

本文提出新的工具，计算连续 stationary 测度下的 Lyapunov 指数和 Hausdorff 维数，并应用于单个数字禁止情况下的维数计算。

Hausdorff dimension of Gauss--Cantor sets and two applications to classical Lagrange and Markov spectra

This paper is dedicated to the study of two famous subsets of the real line, namely Lagrange spectrum $L$ and Markov spectrum $M$. Our first result, Theorem 2.1, provides a rigorous estimate on the smallest value $t_1$ such that the portion of the Markov spectrum $(-\infty,t_1)\cap M$ has Hausdorff dimension $1$. Our second result, Theorem 3.1, gives a new upper bound on the Hausdorff dimension of the set difference $M\setminus L$. Our method combines new facts about the structure of the classical spectra together with finer estimates on the Hausdorff dimension of Gauss--Cantor sets of continu…

非均匀双曲流吸引子的豪斯多夫维数与灵活性

Hausdorff Dimension and Flexibility for Attractors of Non-Uniformly Hyperbolic Flows

该研究将几何洛伦兹吸引子的维数理论推广到更一般的非均匀双曲吸引子，证明此类吸引子含维数大于2的双曲马蹄，建立中间维数性质，得到相关动力学谱的鲁棒非空内部结果。

实射影线上类康托尔集的量化

Quantization of Cantor-Like Set on the Real Projective Line

本文在实射影线上构建迭代函数系统生成类康托尔集，估计其Hausdorff维数并证明概率测度存在性，推导出前推测度与原始测度量化误差的常数倍关系及2阶误差上界。

关于信仰度与由算术康托系列展开生成的DP变换

On faithfulness and DP-transformations generated by arithmetic Cantor series expansions

本文研究了由算术康托系列展开生成的DP变换的信仰度条件及其在单位区间上的维数保持特性。

区间上的分段压缩映射：豪斯多夫维数、熵与吸引子

Piecewise contracting maps on the interval: Hausdorff dimension, entropy and attractors

本文研究紧区间上单射分段压缩映射的吸引子，利用轨道复杂度证明其拓扑熵与豪斯多夫维数均为零。

The Attractor of Renormalization and Rigidity of Towers of Critical Circle Maps

We demonstrate the existence of a global attractor A with a Cantor set structure for the renormalization of critical circle mappings. The set A is invariant under a generalized renormalization transformation, whose action on A is conjugate to the two-sided shift.

素数连分数Cantor集的精确维数

Exact dimensions of the prime continued fraction Cantor set

本文研究了素数Cantor集的Hausdorff维数和packing维数，证明了其Hausdorff测度不能有限正，但在数论猜想下其packing测度关于特定维数函数正且有限。

关于紧吸引子在Hausdorff空间上的拓扑性质

On topological properties of compact attractors on Hausdorff spaces

本文研究了在Hausdorff空间中紧吸引子作为其吸引域强变形抵消的条件。

Basmajian-type identities and Hausdorff dimension of limit sets

In this paper, we study Basmajian-type series identities on holomorphic families of Cantor sets associated to one-dimensional complex dynamical systems. We show that the series is absolutely summable if and only if the Hausdorff dimension of the Cantor set is strictly less than one. Throughout the domain of convergence, these identities can be analytically continued and they exhibit nontrivial monodromy.

产品空间上吸引子和分形函数的研究及维度方面

Study of attractors and fractal functions on the product spaces and Dimensional aspects

本文研究了产品空间上的吸引子与分形函数，探讨了产品Hausdorff度量与吸引子维度的关系，建立了同构性和维度界。

Probabilistic Universality in two-dimensional Dynamics

In this paper we continue to explore infinitely renormalizable Hénon maps with small Jacobian. It was shown in [CLM] that contrary to the one-dimensional intuition, the Cantor attractor of such a map is non-rigid and the conjugacy with the one-dimensional Cantor attractor is at most 1/2-Hölder. Another formulation of this phenomenon is that the scaling structure of the Hénon Cantor attractor differs from its one-dimensional counterpart. However, in this paper we prove that the weight assigned by the canonical invariant measure to these bad spots tends to zero on microscopic scales. This phenom…

Rigorous effective bounds on the Hausdorff dimension of continued fraction Cantor sets: a hundred decimal digits for the dimension of $E_2$

We prove that the algorithm of [13] for approximating the Hausdorff dimension of dynamically defined Cantor sets, using periodic points of the underlying dynamical system, can be used to establish completely rigorous high accuracy bounds on the dimension. The effectiveness of these rigorous estimates is illustrated for Cantor sets consisting of continued fraction expansions with restricted digits. For example the Hausdorff dimension of the set $E_2$ (of those reals whose continued fraction expansion only contains digits 1 and 2) can be rigorously approximated, with an accuracy of over 100 deci…

阻尼波方程全局吸引子的Gromov-Hausdorff稳定性研究：在领域扰动下的连续依赖性

Gromov-Hausdorff stability of global attractors of damped wave equations under perturbations of the domain

本文研究了在领域扰动下阻尼波方程全局吸引子的Gromov-Hausdorff稳定性，利用紧致度量空间之间的距离建立其连续依赖性。

具有弱混合吸引子的区间平移映射

Interval Translation Maps with Weakly Mixing Attractors

针对具有 Cantor 吸引子的双参数区间平移映射族，本文利用类似 Rauzy 归纳的参数空间动力系统 $G$，判定其线性递归性或弱混合性。

Random Delta-Hausdorff-attractors

Global random attractors and random point attractors for random dynamical systems have been studied for several decades. Here we introduce two intermediate concepts: $Δ$-attractors are characterized by attracting all deterministic compact sets of Hausdorff dimension at most $Δ$, where $Δ$ is a non-negative number, while cc-attractors attract all countable compact sets. We provide two examples showing that a given random dynamical system may have various different $Δ$-attractors for different values of $Δ$. It seems that both concepts are new even in the context of deterministic dynamical syste…

Absorbing Cantor sets in dynamical systems: Fibonacci maps

In this paper we shall show that there exists a polynomial unimodal map f: [0,1] -> [0,1] which is 1) non-renormalizable(therefore for each x from a residual set, $ω(x)$ is equal to an interval), 2) for which $ω(c)$ is a Cantor set, and 3) for which $ω(x)=ω(c)$ for Lebesgue almost all x. So the topological and the metric attractor of such a map do not coincide. This gives the answer to a question posed by Milnor.

Intersections of middle-$α$ Cantor sets with a fixed translation

For $λ\in(0,1/3]$ let $C_λ$ be the middle-$(1-2λ)$ Cantor set in $\mathbb R$. Given $t\in[-1,1]$, excluding the trivial case we show that \[ Λ(t):=\left\{λ\in(0,1/3]: C_λ\cap(C_λ+t)\ne\emptyset\right\} \] is a topological Cantor set with zero Lebesgue measure and full Hausdorff dimension. In particular, we calculate the local dimension of $Λ(t)$, which reveals a dimensional variation principle. Furthermore, for any $β\in[0,1]$ we show that the level set \[ Λ_β(t):=\left\{λ\inΛ(t): \dim_H(C_λ\cap(C_λ+t))=\dim_P(C_λ\cap(C_λ+t))=β\frac{\log 2}{-\log λ}\right\} \] has equal Hausdorff and packing d…

Intersections of multiplicative translates of 3-adic Cantor sets

Motivated by a question of Erdős, this paper considers questions concerning the discrete dynamical system on the 3-adic integers given by multiplication by 2. Let the 3-adic Cantor set consist of all 3-adic integers whose expansions use only the digits 0 and 1. The exception set is the set of 3-adic integers whose forward orbits under this action intersects the 3-adic Cantor set infinitely many times. It has been shown that this set has Hausdorff dimension 0. Approaches to upper bounds on the Hausdorff dimensions of these sets leads to study of intersections of multiplicative translates of Can…

牛顿法的典型动力学

Typical dynamics of Newton's method

本文证明对典型连续可微函数，牛顿法轨迹除发散或收敛到根外，还可能以康托尔集为吸引子，且此类吸引子上的动力学均由同一类加法机描述并拓扑等价。

Moreira's Theorem on the arithmetic sum of dynamically defined Cantor sets

We present a complete proof of a theorem of C.G. Moreira. Under mild checkable conditions, the theorem asserts that the Hausdorff dimension of the arithmetic sum of two dynamically defined Cantor subsets of the real line, equals either the sum of the dimensions or 1, whichever is smaller.

自仿集类的Hausdorff维数

Hausdorff Dimension of a Class of Self-Affine Sets

本文推导了由仿射迭代函数系统生成的自仿集类的精确Hausdorff维数公式，结合了收缩相似变换与对称算子A^T A的线性部分，统一了混合系统的方法，证明了参数平衡c + r = 1对吸引子连通性和开放集条件的保证。

The Hausdorff dimension of the projections of self-affine carpets

We study the orthogonal projections of a large class of self-affine carpets, which contains the carpets of Bedford and McMullen as special cases. Our main result is that if $Λ$ is such a carpet, and certain natural irrationality conditions hold, then every orthogonal projection of $Λ$ in a non-principal direction has Hausdorff dimension $\min(γ,1)$, where $γ$ is the Hausdorff dimension of $Λ$. This generalizes a recent result of Peres and Shmerkin on sums of Cantor sets.

对称Fibonacci双峰映射存在野生吸引子

Wild attractor exists for symmetric Fibonacci bimodal map

本文证明对称Fibonacci双峰映射在临界阶足够大时，其临界点的公共ω-极限集为野生Cantor吸引子，并通过半共轭将问题简化为Fibonacci盒映射。

Rigorous bounds on the Hausdorff dimension of Feigenbaum attractors

We calculate rigorous bounds on the Hausdorff dimension of the attractor at the accumulation of the period-doubling cascade for families of maps with quadratic, cubic, and quartic critical point. To do this, we express the attractors as the limit sets of appropriate Iterated Function Systems constructed using rigorous bounds on the corresponding renormalisation fixed point functions. We use interval arithmetic with rigorous directed rounding modes to show that the respective dimensions lie in subintervals of the intervals (0.5370,0.5392), (0.6040,0.6091), and (0.6395,0.6474).

无界域上时滞反应扩散方程全局吸引子的拓扑维数

Topological dimensions of global attractors for a delayed reaction-diffusion equation on an unbounded domain

研究无界域上时滞反应扩散方程全局吸引子的Hausdorff与分形维数估计，通过辅助Hilbert空间重述方程并利用扰动半群方法证明全局解与吸引子存在性，最终获得维数上界。

The multipliers of periodic points in one-dimensional dynamics

It will be shown that the smooth conjugacy class of an $S-$unimodal map which does not have a periodic attractor neither a Cantor attractor is determined by the multipliers of the periodic orbits. This generalizes a result by M.Shub and D.Sullivan for smooth expanding maps of the circle.

多维准周期Schrödinger算子的Cantor谱

Cantor spectrum for multidimensional quasi-periodic Schrödinger operators

研究多维准周期Schrödinger算子的Cantor谱问题，证明临界近正交算子的谱Hausdorff维数可任意小但非零。

Non-smooth saddle-node bifurcations II: dimensions of strange attractors

We study the geometric and topological properties of strange non-chaotic attractors created in non-smooth saddle-node bifurcations of quasiperiodically forced interval maps. By interpreting the attractors as limit objects of the iterates of a continuous curve and controlling the geometry of the latter, we determine their Hausdorff and box-counting dimension and show that these take distinct values. Moreover, the same approach allows to describe the topological structure of the attractors and to prove their minimality.

Estimates of Hausdorff dimension for non-wandering sets of higher dimensional open billiards

This article concerns a class of open billiards consisting of a finite number of strictly convex, non-eclipsing obstacles $K$. The non-wandering set $M_0$ of the billiard ball map is a topological Cantor set and its Hausdorff dimension has been previously estimated for billiards in $\mathbb{R}^2$, using well-known techniques. We extend these estimates to billiards in $\mathbb{R}^n$, and make various refinements to the estimates. These refinements also allow improvements to other results. We also show that in many cases, the non-wandering set is confined to a particular subset of $\mathbb{R}^n$…

Intersections of multiplicative translates of $3$-adic Cantor sets II: two infinite families

This paper continues the study of the structure of finite intersections of general multiplicative translates $\mathcal{C}(M_1,\ldots,M_n)=\frac{1}{M_1}Σ_{3,\bar{2}}\cap\cdots\cap\frac{1}{M_n}Σ_{3,\bar{2}}$ for integers $1\leq M_1<\cdots<M_n$, where $Σ_{3,\bar{2}}$ denotes the $3$-adic Cantor set. This study was motivated by questions concerning the discrete dynamical system on the $3$-adic integers $\mathbb{Z}_3$ given by multiplication by $2$. The exceptional set $\mathcal{E}(\mathbb{Z}_3)$ is defined to be the set of all elements of $\mathbb{Z}_3$ whose forward orbits under this action inter…

Shrinking targets for non-autonomous dynamical systems corresponding to Cantor series expansions

We provide a closed formula of Bowen type for the Hausdorff dimension of a very general shrinking target scheme generated by the non-autonomous dynamical system on the interval $[0,1)$, viewed as $\mathbb{R}/\mathbb{Z}$, corresponding to a given method of Cantor series expansion. We also examine a wide class of examples utilizing our theorem. In particular, we provide a Diophantine approximation interpretation of our scheme.

Dimension of a class of intrinsically transversal solenoidal attractors in high dimensions

We study the fractal dimension of a class of solenoidal attractors in dimensions greater or equal than 3, proving that if the contraction is sufficiently strong, the expansion is close to conformal and the attractor satisfy a geometrical condition of transversality between its components, then the Hausdorff and box-counting dimension of every stable section of the attractor have the same value, which corresponds to the zero of the topological pressure as in Bowen's formula. We also calculate the dimension of the attractor and prove that it is continuous in this class.

Cantor测度的密度谱

Density spectrum of Cantor measure

本文研究了Cantor测度的逐点密度谱，通过引入涉及倍增映射的等价二进版本，结合开放动力系统熵与调谐概念，完整刻画了上下密度取值集合及其水平集的Hausdorff维数。

Affine embeddings of Cantor sets and dimension of $αβ$-sets

Let $E, F\subset {\Bbb R}^d$ be two self-similar sets, and suppose that $F$ can be affinely embedded into $E$. Under the assumption that $E$ is dust-like and has a small Hausdorff dimension, we prove the logarithmic commensurability between the contraction ratios of $E$ and $F$. This gives a partial affirmative answer to Conjecture 1.2 in \cite{FHR14}. The proof is based on our study of the box-counting dimension of a class of multi-rotation invariant sets on the unit circle, including the $αβ$-sets initially studied by Engelking and Katznelson.

Sums of regular Cantor sets of large dimension and the Square Fibonacci Hamiltonian

We show that under natural technical conditions, the sum of a $C^2$ dynamically defined Cantor set with a compact set in most cases (for almost all parameters) has positive Lebesgue measure, provided that the sum of the Hausdorff dimensions of these sets exceeds one. As an application, we show that for many parameters, the Square Fibonacci Hamiltonian has spectrum of positive Lebesgue measure, while at the same time the density of states measure is purely singular.

Conformality for a robust class of non-conformal attractors

In this paper we investigate the Hausdorff dimension of limit sets of Anosov representations. In this context we revisit and extend the framework of hyperconvex representations and establish a convergence property for them, analogue to a differentiability property. As an application of this convergence, we prove that the Hausdorff dimension of the limit set of a hyperconvex representation is equal to a suitably chosen critical exponent.