Almost topological dynamical systems

For the notion of finitary isomorphism, which arises in many examples in ergodic theory, we prove some basic theorems about invariants, representations and the central limit theorem in shift spaces.     

Universal minimal topological dynamical systems

Rokhlin (1963) showed that any aperiodic dynamical system with finite entropy admits a countable generating partition. Krieger (1970) showed that aperiodic ergodic systems with entropy < log a, admit a generating partition with no more than a sets. In Symbolic Dynamics terminology, these results can be phrased— ℕ^ℤ is a universal system in the category of aperiodic systems, and [a]^ℤ is a universal system for aperiodic ergodic systems with entropy < log a. Weiss ([We89], 1989) presented a Minimal system, on a Compact space (a subshift of ) which is universal for aperiodic systems. In this work we present a joint generalization of both results: given ɛ, there exists a minimal subshift of [a]^ℤ, universal for aperiodic ergodic systems with entropy < log a − ɛ.     

Rapid fluctuation for topological dynamical systems

In this paper, we introduce a new notion called rapid fluctuation to characterize the complexity of a general topological dynamical system. As a continuation of the former work [Huang, Chen, Ma, J. Math. Anal. Appl., 2006, 323: 228–252], here we prove that a Lipschitz dynamical system defined on a compact metric space has a rapid fluctuation if it has either a quasi shift invariant set or a topological horseshoe. As an application, the rapid fluctuation of a discrete predator-prey model is considered.      

Ubiquity of odometers in topological dynamical systems

Let M be the Cantor space or an n-manifold with C(M,M) the set of continuous self-maps of M. We prove the following:

(1)

There is a residual set of points (x,f) in M×C(M,M) all of which generate as their ω-limit set a particular, unique adding machine.

(2)

Moreover, if M has the fixed point property, then a generic f∈C(M,M) generates uncountably many distinct copies of every possible adding machine.

     

The product structure of finitely presented dynamical systems

We consider finitely presented systems, which were introduced by Fried, and examine the circumstances under which these systems have canonical coordinates. We give necessary and sufficient conditions for their existence in a combinatorial way.     

The topological product structure of systems of Lebesgue spaces

The first author was in part supported by the Research Grants Committee of the University of Alabama-Project 1530     

On properties of the topological entropy of dynamical systems

In this paper, the dependence on the parameter of the topological entropy of dynamical systems continuously depending on the parameter is studied from the point of view of the Baire classification of functions.     

Nilsequences and a structure theorem for topological dynamical systems

We characterize inverse limits of nilsystems in topological dynamics, via a structure theorem for topological dynamical systems that is an analog of the structure theorem for measure preserving systems. We provide two applications of the structure. The first is to nilsequences, which have played an important role in recent developments in ergodic theory and additive combinatorics; we give a characterization that detects if a given sequence is a nilsequence by only testing properties locally, meaning on finite intervals. The second application is the construction of the maximal nilfactor of any order in a distal minimal topological dynamical system. We show that this factor can be defined via a certain generalization of the regionally proximal relation that is used to produce the maximal equicontinuous factor and corresponds to the case of order 1.     

Some problems on fractal geometry and topological dynamical systems

This paper is a continuation of [14], some new problems on fractal geometry and topological dynamical systems have been posed.     

Lower bounds of the topological entropy for nonautonomous dynamical systems

In this paper, lower bounds of the topological entropy for nonautonomous dynamical systems are given via the growths of topological complexity in fundamental group and in degree.     

非自治动力系统拓扑压变分原理的一点注记

用类似于非自治熵的变分原理的方法,证明了非自治拓扑压的变分原理的一个不等式,推广了非自治熵的变分原理,丰富了非自治变分原理的内容.     

Structure of attractors for skew product semiflows

In this work we study the continuity and structural stability of the uniform attractor associated with non-autonomous perturbations of differential equations. By a careful study of the different definitions of attractor in the non-autonomous framework, we introduce the notion of lifted-invariance on the uniform attractor, which becomes compatible with the dynamics in the global attractor of the associated skew product semiflow, and allows us to describe the internal dynamics and the characterization of the uniform attractors. The associated pullback attractors and their structural stability under perturbations will play a crucial role.     

The topological centre of a compactification of a locally compact group

This research was supported in part by NSERC grant A7679 and SERC grant GR/H31172     

Category of topological jet manifolds and certain applications in the theory of nonlinear infinite-dimensional dynamical systems

A new category of topological jet manifolds is proposed for the purpose of investigating exact finite-dimensional approximations of nonlinear dynamical systems on infinite-dimensional functional manifolds. Differential geometry structures on these manifolds and their applications to the theory of integrability in quadratures of nonlinear dynamical Lax-type systems are studied.Translated from Ukrayins'kyy Matematychnyy Zhurnal, Vol. 44, No. 9, pp. 1242–1256, September, 1992.     

A non-Bernoulli skew product which is loosely Bernoulli

LetT: Y→Y be the Bernoulli two shift with independent generatorQ={Q ₀,Q ₁} and letS: X→X be a measure preserving bijection. If (S, X) is ergodic then the skew product onX×Y defined by {fx339-1} is aK-automorphism. IfŜ is also Bernoulli we sayS is pre-Bernoulli. J. Feldman showed that ifS is pre-Bernoulli thenS must be loosely Bernoulli. We construct an example to show the converse is false, i.e. anS that is loosely Bernoulli but not pre-Bernoulli.