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The fixed point set of open mappings on extremally disconnected spaces

Egbert Thümmel (1994)

Commentationes Mathematicae Universitatis Carolinae

We give an example of an extremally disconnected compact Hausdorff space with an open continuous selfmap such that the fixed point set is nonvoid and nowhere dense, respṫhat there is exactly one nonisolated fixed point.

The full periodicity kernel of the trefoil

Carme Leseduarte, Jaume Llibre (1996)

Annales de l'institut Fourier

We consider the following topological spaces: O = { z : | z + i | = 1 } , O 3 = O { z : z 4 [ 0 , 1 ] , Im z 0 } , O 4 = O { z : z 4 [ 0 , 1 ] } , 1 = O : | z - i | = 1 } { z : z [ 0 , 1 ] } , 2 = 1 { z : z 2 [ 0 , 1 ] } , et T = { z : z = cos ( 3 θ ) e i θ , 0 θ 2 π } . Set E { O 3 , O 4 , 1 , 2 , T } . An E map f is a continuous self-map of E having the branching point fixed. We denote by Per ( f ) the set of periods of all periodic points of f . The set K is the full periodicity kernel of E if it satisfies the following two conditions: (1) If f is an E map and K Per ( f ) , then Per ( f ) = . (2) If S is a set such that for every E map f , S Per ( f ) implies Per ( f ) = , then K S . In this paper we compute the full periodicity kernel of O 3 , O 4 , 1 , 2 and T .

The geometry of laminations

Robbert Fokkink, Lex Oversteegen (1996)

Fundamenta Mathematicae

A lamination is a continuum which locally is the product of a Cantor set and an arc. We investigate the topological structure and embedding properties of laminations. We prove that a nondegenerate lamination cannot be tree-like and that a planar lamination has at least four complementary domains. Furthermore, a lamination in the plane can be obtained by a lakes of Wada construction.

The nonexistence of expansive homeomorphisms of chainable continua

Hisao Kato (1996)

Fundamenta Mathematicae

A homeomorphism f:X → X of a compactum X with metric d is expansive if there is c > 0 such that if x, y ∈ X and x ≠ y, then there is an integer n ∈ ℤ such that d ( f n ( x ) , f n ( y ) ) > c . In this paper, we prove that if a homeomorphism f:X → X of a continuum X can be lifted to an onto map h:P → P of the pseudo-arc P, then f is not expansive. As a corollary, we prove that there are no expansive homeomorphisms on chainable continua. This is an affirmative answer to one of Williams’ conjectures.

The nonexistence of universal metric flows

Stefan Geschke (2018)

Commentationes Mathematicae Universitatis Carolinae

We consider dynamical systems of the form ( X , f ) where X is a compact metric space and f : X X is either a continuous map or a homeomorphism and provide a new proof that there is no universal metric dynamical system of this kind. The same is true for metric minimal dynamical systems and for metric abstract ω -limit sets, answering a question by Will Brian.

The omega limit sets of subsets in a metric space

Changming Ding (2005)

Czechoslovak Mathematical Journal

In this paper, we discuss the properties of limit sets of subsets and attractors in a compact metric space. It is shown that the ω -limit set ω ( Y ) of Y is the limit point of the sequence { ( C l Y ) · [ i , ) } i = 1 in 2 X and also a quasi-attractor is the limit point of attractors with respect to the Hausdorff metric. It is shown that if a component of an attractor is not an attractor, then it must be a real quasi-attractor.

Currently displaying 381 – 400 of 523