Tilings in topological spaces.
Topological zero-one laws
Topologies in product which preserve Baire spaces
Two generic results in fixed point theory
We give two examples of the generic approach to fixed point theory. The first example is concerned with the asymptotic behavior of infinite products of nonexpansive mappings in Banach spaces and the second with the existence and stability of fixed points of continuous mappings in finite-dimensional Euclidean spaces.
Un critère de métrisabilité d’un convexe compact à partir de
Uniformly distributed sequences of positive integers in Baire's space
Universally Kuratowski–Ulam spaces
We introduce the notions of Kuratowski-Ulam pairs of topological spaces and universally Kuratowski-Ulam space. A pair (X,Y) of topological spaces is called a Kuratowski-Ulam pair if the Kuratowski-Ulam Theorem holds in X× Y. A space Y is called a universally Kuratowski-Ulam (uK-U) space if (X,Y) is a Kuratowski-Ulam pair for every space X. Obviously, every meager in itself space is uK-U. Moreover, it is known that every space with a countable π-basis is uK-U. We prove the following: ...
Weak calibers and the Scott-Watson theorem
Weak continuity properties of topologized groups
We explore (weak) continuity properties of group operations. For this purpose, the Novak number and developability number are applied. It is shown that if is a regular right (left) semitopological group with such that all left (right) translations are feebly continuous, then is a topological group. This extends several results in literature.
Whitney C...-topologies and the Baire property.
-fuzzy compactness in -topological spaces.
-porosity in monotonic analysis with applications to optimization.
-porosity is separably determined
We prove a separable reduction theorem for -porosity of Suslin sets. In particular, if is a Suslin subset in a Banach space , then each separable subspace of can be enlarged to a separable subspace such that is -porous in if and only if is -porous in . Such a result is proved for several types of -porosity. The proof is done using the method of elementary submodels, hence the results can be combined with other separable reduction theorems. As an application we extend a theorem...
О пополнениях топологических групп
О применении повторных нестандартных расширений в топологии.