Über die Erzeugung von eigentlichen Transformationsgruppen.
Ueber D-Minimale Aktionen von Zusammen-Haengenden Lie-Gruppen
Ultrafilter-limit points in metric dynamical systems
Given a free ultrafilter on and a space , we say that is the -limit point of a sequence in (in symbols, -) if for every neighborhood of , . By using -limit points from a suitable metric space, we characterize the selective ultrafilters on and the -points of . In this paper, we only consider dynamical systems , where is a compact metric space. For a free ultrafilter on , the function is defined by - for each . These functions are not continuous in general. For a...
Ultrafiltres absolus
Ultrafiltres absolus et problèmes d'extraction de sous-suites
Un crible généralisé
Un critère de métrisabilité d’un convexe compact à partir de
Una generalizzazione di certe algebre che intervengono nella teoria dei sistemi
Un'algebra locale reticolata che interviene nella teoria dei sistemi
Uncountable ω-limit sets with isolated points
We give two examples of tent maps with uncountable (as it happens, post-critical) ω-limit sets, which have isolated points, with interesting structures. Such ω-limit sets must be of the form C ∪ R, where C is a Cantor set and R is a scattered set. Firstly, it is known that there is a restriction on the topological structure of countable ω-limit sets for finite-to-one maps satisfying at least some weak form of expansivity. We show that this restriction does not hold if the ω-limit set is uncountable....
Une approche métrique de la rétraction dans les ensembles ordonnés et les graphes
Une classe d'espaces de Banach qui admettent des quotients séparables
Une démonstration du théorème de séparation des ensembles analytiques
Une démonstration du théorème de Souslin-Lusin
Une généralisation du développement en fraction continue
Une propriété extrémale de la suite de Thue-Morse en rapport avec les cascades de Feigenbaum
Une remarque sur les espaces sousliniens de Bourbaki
Une topolgie du monoide libre.
Une version feuilletée équivariante du théorème de translation de Brouwer
The Brouwer’s plane translation theorem asserts that for a fixed point free orientation preserving homeomorphism f of the plane, every point belongs to a Brouwer line: a proper topological embedding C of R, disjoint from its image and separating f(C) and f–1(C). Suppose that f commutes with the elements of a discrete group G of orientation preserving homeomorphisms acting freely and properly on the plane. We will construct a G-invariant topological foliation of the plane by Brouwer lines. We apply...
Uniform asymptotic normal structure, the uniform semi-opial property, and fixed points of asymptotically regular uniformly Lipschitzian semigroups. II.