The approximation and extension of uniformly continuous Banach space valued mappings
The Dugundji extension property can fail in ωµ -metrizable spaces
We show that there exist -metrizable spaces which do not have the Dugundji extension property ( with the countable box topology is such a space). This answers a question posed by the second author in 1972, and shows that certain results of van Douwen and Borges are false.
The Dugundji extension theorem and extension degree
The homotopies of admissible multivalued mappings
Certain properties of homotopies of admissible multivalued mappings shall be presented, along with their applications as the tool for examining the acyclicity of a space.
The Interval [0,1] Admits no Functorial Embedding into a Finite-Dimensional or Metrizable Topological Group
An embedding X ⊂ G of a topological space X into a topological group G is called functorial if every homeomorphism of X extends to a continuous group homomorphism of G. It is shown that the interval [0, 1] admits no functorial embedding into a finite-dimensional or metrizable topological group.
The Lefschetz fixed point theorem for multivalued maps of non-metrizable spaces
The Lefschetz fixed point theorem for some noncompact multi-valued maps
The Lusin-Menchoff property of fine topologies
The set of exponents for isomorphic extensions of Hölder maps is not always closed.
Tietze's extension theorem.
Topological compactifications
We study those compactifications of a space such that every autohomeomorphism of the space can be continuously extended over the compactification. These are called H-compactifications. Van Douwen proved that there are exactly three H-compactifications of the real line. We prove that there exist only two H-compactifications of Euclidean spaces of higher dimension. Next we show that there are 26 H-compactifications of a countable sum of real lines and 11 H-compactifications of a countable sum of Euclidean...
Two extension theorems for functions