A Poincaré formula for the fixed point indices of the iterates of arbitrary planar homeomorphisms.
A pointwise contraction criteria for the existence of fixed points.
A Polish AR-Space with no Nontrivial Isotopy
The Polish space Y constructed in [vM1] admits no nontrivial isotopy. Yet, there exists a Polish group that acts transitively on Y.
A proof of the Schauder-Tychonoff theorem.
A property of the Sorgenfrey line
A quest for nice kernels of neighbourhood assignments
Given a topological property (or a class) , the class dual to (with respect to neighbourhood assignments) consists of spaces such that for any neighbourhood assignment there is with and . The spaces from are called dually . We continue the study of this duality which constitutes a development of an idea of E. van Douwen used to define -spaces. We prove a number of results on duals of some general classes of spaces establishing, in particular, that any generalized ordered space...
A random fixed point theorem for multivalued mappings
A reconstruction theorem for locally moving groups acting on completely metrizable spaces
Let G be a group which acts by homeomorphisms on a metric space X. We say the action of G is locally moving on X if for every open U ⊆ X there is a g ∈ G such that g↾X ≠ Id while g↾(X∖U) = Id. We prove the following theorem: Theorem A. Let X,Y be completely metrizable spaces and let G be a group which acts on X and Y with locally moving actions. If the orbits of the action of G on X are of the second category in X and the orbits of the action of G on Y are of the second category...
A related fixed point theorem in complete metric spaces.
A related fixed point theorem in two fuzzy metric spaces.
A relatively free topological group that is not varietal free
Answering a 1982 question of Sidney A. Morris, we construct a topological group G and a subspace X such that (i) G is algebraically free over X, (ii) G is relatively free over X, that is, every continuous mapping from X to G extends to a unique continuous endomorphism of G, and (iii) G is not a varietal free topological group on X in any variety of topological groups.
A remark on a theorem of Solecki
S. Solecki proved that if is a system of closed subsets of a complete separable metric space , then each Suslin set which cannot be covered by countably many members of contains a set which cannot be covered by countably many members of . We show that the assumption of separability of cannot be removed from this theorem. On the other hand it can be removed under an extra assumption that the -ideal generated by is locally determined. Using Solecki’s arguments, our result can be used...
A remark on common fixed sets of commuting mappings
A remark on Rhoades fixed point theorem for non-self mappings.
A remark on second order functional-differential systems
It is proved that under some conditions the set of solutions to initial value problem for second order functional differential system on an unbounded interval is a compact -set and hence nonvoid, compact and connected set in a Fréchet space. The proof is based on a Kubáček’s theorem.
A remark on small divisors problems
A Remark on the Paper ''Fixed Point Mappings on Compact Metric Spaces''
A Remark on the Topological Entropy of Homeomorphisms.
A remark on the uniformization in metric ѕpaces
A rest point free dynamical system on with uniformly bounded trajectories