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On a shadowing lemma in metric spaces

Tibor Žáčik (1992)

Mathematica Bohemica

In the present paper conditions are studied, under which a pseudo-orbit of a continuous map f : M M , where M is a metric space, is shadowed, in a more general sense, by an accurate orbit of the map f .

On absolute stability

Roger C. McCann (1972)

Annales de l'institut Fourier

Absolute stability of a compact set is characterized by the cardinality of a fundamental system of positively invariant neighborhoods.

On composants of solenoids

Ronald de Man (1995)

Fundamenta Mathematicae

It is proved that any two composants of any two solenoids are homeomorphic.

On continuous actions commutingwith actions of positive entropy

Mark Shereshevsky (1996)

Colloquium Mathematicae

Let F and G be finitely generated groups of polynomial growth with the degrees of polynomial growth d(F) and d(G) respectively. Let S = S f f F be a continuous action of F on a compact metric space X with a positive topological entropy h(S). Then (i) there are no expansive continuous actions of G on X commuting with S if d(G)

On entropy of patterns given by interval maps

Jozef Bobok (1999)

Fundamenta Mathematicae

Defining the complexity of a green pattern exhibited by an interval map, we give the best bounds of the topological entropy of a pattern with a given complexity. Moreover, we show that the topological entropy attains its strict minimum on the set of patterns with fixed eccentricity m/n at a unimodal X-minimal case. Using a different method, the last result was independently proved in[11].

On enveloping semigroups of almost one-to-one extensions of minimal group rotations

Rafał Pikuła (2012)

Colloquium Mathematicae

We consider a class of symbolic systems over a finite alphabet which are minimal almost one-to-one extensions of rotations of compact metric monothetic groups and provide computations of their enveloping semigroups that highlight their algebraic structure. We describe the set of idempotents of these semigroups and introduce a classification that can help distinguish between certain such systems having zero topological entropy.

On enveloping semigroups of nilpotent group actions generated by unipotent affine transformations of the torus

Rafał Pikuła (2010)

Studia Mathematica

Let G be a group generated by a set of affine unipotent transformations T: X → X of the form T(x) = A x + α, where A is a lower triangular unipotent matrix, α is a constant vector, and X is a finite-dimensional torus. We show that the enveloping semigroup E(X,G) of the dynamical system (X,G) is a nilpotent group and find upper and lower bounds on its nilpotency class. Also, we obtain a description of E(X,G) as a quotient space.

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