Mixing sets, positive entropy homeomorphisms and non-Suslinean continua

2015 ◽  
Vol 36 (7) ◽  
pp. 2246-2257 ◽  
Author(s):  
CHRISTOPHER MOURON

Let $\{h_{n}\}_{n\in \mathbb{N}}$ be a sequence of self maps on a metric space $X$. We say that $Q\subset X$ is a mixing set on $\{h_{n}\}_{n\in \mathbb{N}}$ if for every $V\subset Q$ such that $\text{int}_{Q}(V)\not =\emptyset$ and every $\unicode[STIX]{x1D716}>0$ there exists $N=N(V,\unicode[STIX]{x1D716})$ such that $\text{d}_{H}(Q,h_{n}(V))<\unicode[STIX]{x1D716}$ for all $n\geq N$, where $\text{d}_{H}$ is the Hausdorff metric. It is shown that if $Q$ is a non-degenerate mixing set for a sequence of homeomorphisms on a continuum, then the continuum must be non-Suslinean. This is generalized to the notion of a $\unicode[STIX]{x1D719}$-mixing set. As a corollary, it is shown that a continuum must be non-Suslinean in order to admit a positive entropy homeomorphism.

2017 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Sagita Charolina Sihombing ◽  
Ety Septiati

In this paper, we study the existence of fixed point of the φ-weak contraction mapping in the complete partial metric space for multivalued mapping. Distance calculations are performed using Hausdorff metric. The result obtained in this paper is an extension of similar result for single valued mapping.


2009 ◽  
Vol 61 (2) ◽  
pp. 299-314 ◽  
Author(s):  
Robert J. MacG. Dawson and ◽  
Maria Moszyńska

Abstract. A set in a metric space is called a Čebyšev set if it has a unique “nearest neighbour” to each point of the space. In this paper we generalize this notion, defining a set to be Čebyšev relative to another set if every point in the second set has a unique “nearest neighbour” in the first. We are interested in Čebyšev sets in some hyperspaces over Rn, endowed with the Hausdorff metric, mainly the hyperspaces of compact sets, compact convex sets, and strictly convex compact sets. We present some new classes of Čebyšev and relatively Čebyšev sets in various hyperspaces. In particular, we show that certain nested families of sets are Čebyšev. As these families are characterized purely in terms of containment,without reference to the semi-linear structure of the underlyingmetric space, their properties differ markedly from those of known Čebyšev sets.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Heng Liu ◽  
Fengchun Lei ◽  
Lidong Wang

Consider the surjective, continuous mapf:X→Xand the continuous mapf¯of𝒦(X)induced byf, whereXis a compact metric space and𝒦(X)is the space of all nonempty compact subsets ofXendowed with the Hausdorff metric. In this paper, we give a short proof that iff¯is Li-Yoke sensitive, thenfis Li-Yorke sensitive. Furthermore, we give an example showing that Li-Yorke sensitivity offdoes not imply Li-Yorke sensitivity off¯.


2004 ◽  
Vol 04 (03) ◽  
pp. 373-384 ◽  
Author(s):  
DESHENG LI ◽  
P. E. KLOEDEN

The equi-attraction properties of uniform pullback attractors [Formula: see text] of nonautonomous dynamical systems (θ,ϕλ) with a parameter λ∈Λ, where Λ is a compact metric space, are investigated; here θ is an autonomous dynamical system on a compact metric space P which drives the cocycle ϕλon a complete metric state space X. In particular, under appropriate regularity conditions, it is shown that the equi-attraction of the family [Formula: see text] uniformly in p∈P is equivalent to the continuity of the setvalued mappings [Formula: see text] in λ with respect to the Hausdorff metric on the nonempty compact subsets of X.


1967 ◽  
Vol 19 ◽  
pp. 242-250 ◽  
Author(s):  
W. T. Ingram

In this paper it is proved that if a circle-like continuum M cannot be embedded in the plane, then M is not a continuous image of any plane continuum (Theorem 5).Suppose that (S, ρ) is a metric space. A finite sequence of domains L1, L2, … , Ln is called a linear chain provided Li intersects Lj if and only if |i — j| ⩽ 1. If, in addition, there is a positive number ∊ such that, for each i, the diameter of Li is less than ∊, then the linear chain is called a linear ∊-chain. If for each positive number ∊ the continuum M can be covered by a linear ∊-chain, then M is said to be chainable (or snake-like) (2).


2018 ◽  
Vol 20 (07) ◽  
pp. 1750086 ◽  
Author(s):  
Keonhee Lee ◽  
C. A. Morales ◽  
Bomi Shin

We prove that the set of expansive measures of a homeomorphism of a compact metric space is a [Formula: see text] subset of the space of Borel probability measures equipped with the weak* topology. Next that every expansive measure of a homeomorphism of a compact metric space can be weak* approximated by expansive measures with invariant support. In addition, if the expansive measures of a homeomorphism of a compact metric space are dense in the space of Borel probability measures, then there is an expansive measure whose support is both invariant and close to the whole space with respect to the Hausdorff metric. Henceforth, if the expansive measures are dense in the space of Borel probability measures, the set of heteroclinic points has no interior and the space has no isolated points.


Author(s):  
I. N. Kostin

The problem of approximation of attractors for semidynamical systems (SDSs) in a metric space is studied. Let some (exact) SDS possessing an attractor M be inaccurately defined, i.e. let another (approximate) SDS, which is close in some sense to the exact one, be given. The problem is to construct a set , which is close to M in the Hausdorff metric.The suggested procedure for constructing is finite, which makes it possible to use it in computations. The results obtained are suitable for numerical approximation of attractors for a rather large class of semidynamical systems, including ones generated by the Lorenz equations and the Navier–Stokes equations.


1974 ◽  
Vol 75 (2) ◽  
pp. 193-197 ◽  
Author(s):  
A. J. Ostaszewski

AbstractA theorem of Besicovitch, namely that, assuming the continuum hypothesis, there exists in any uncountable complete separable metric space a set of cardinality the continuum all of whose Hausdorif h-measures are zero, is here deduced by appeal to Martin's Axiom. It is also shown that for measures λ of Hausdorff type the union of fewer than 2ℵ0 sets of λ-measure zero is also of λ-measure zero; furthermore, the union of fewer than 2ℵ0 λ-measurable sets is λ-measurable.


Author(s):  
Thomas Weighill ◽  
Takamitsu Yamauchi ◽  
Nicolò Zava

AbstractWe consider infinite-dimensional properties in coarse geometry for hyperspaces consisting of finite subsets of metric spaces with the Hausdorff metric. We see that several infinite-dimensional properties are preserved by taking the hyperspace of subsets with at most n points. On the other hand, we prove that, if a metric space contains a sequence of long intervals coarsely, then its hyperspace of finite subsets is not coarsely embeddable into any uniformly convex Banach space. As a corollary, the hyperspace of finite subsets of the real line is not coarsely embeddable into any uniformly convex Banach space. It is also shown that every (not necessarily bounded geometry) metric space with straight finite decomposition complexity has metric sparsification property.


2003 ◽  
Vol 4 (2) ◽  
pp. 377 ◽  
Author(s):  
Camillo Constantini ◽  
Wieslaw Kubís

<p>We prove that the hyperspace of closed bounded sets with the Hausdor_ topology, over an almost convex metric space, is an absolute retract. Dense subspaces of normed linear spaces are examples of, not necessarily connected, almost convex metric spaces. We give some necessary conditions for the path-wise connectedness of the Hausdorff metric topology on closed bounded sets. Finally, we describe properties of a separable metric space, under which its hyperspace with the Wijsman topology is path-wise connected.</p>


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