A classification of H-closed extensions
A continuous operator extending fuzzy ultrametrics
We consider the problem of simultaneous extension of fuzzy ultrametrics defined on closed subsets of a complete fuzzy ultrametric space. We construct an extension operator that preserves the operation of pointwise minimum of fuzzy ultrametrics with common domain and an operation which is an analogue of multiplication by a constant defined for fuzzy ultrametrics. We prove that the restriction of the extension operator onto the set of continuous, partial fuzzy ultrametrics is continuous with respect...
A continuous operator extending ultrametrics
The problem of continuous simultaneous extension of all continuous partial ultrametrics defined on closed subsets of a compact zero-dimensional metric space was recently solved by E.D. Tymchatyn and M. Zarichnyi and improvements to their result were made by I. Stasyuk. In the current paper we extend these results to complete, bounded, zero-dimensional metric spaces and to both continuous and uniformly continuous partial ultrametrics.
A note on operators extending partial ultrametrics
We consider the question of simultaneous extension of partial ultrametrics, i.e. continuous ultrametrics defined on nonempty closed subsets of a compact zero-dimensional metrizable space. The main result states that there exists a continuous extension operator that preserves the maximum operation. This extension can also be chosen so that it preserves the Assouad dimension.
A simultaneous selection theorem
We prove a theorem that generalizes in a way both Michael's Selection Theorem and Dugundji's Simultaneous Extension Theorem. We use it to prove that if K is an uncountable compact metric space and X a Banach space, then C(K,X) is isomorphic to C(𝓒,X) where 𝓒 denotes the Cantor set. For X = ℝ, this gives the well known Milyutin Theorem.
A study of -spaces and -spaces.
A survey of Dugundji Extension Theory
A theory of absolute proper retracts
A universal metacompact developable -space of weight m
A universal separable metric locally finite-dimensional space
Absolutely minimizing Lipschitz extensions on a metric space.
Almost -continuous functions.
An extension theorem for continuous functions
An extension theorem for multifunctions and a characterization of complete metric spaces
An internal characterization of WI spaces
Another application of the Effros theorem to the pseudo-arc
Another generalization of the Dugundji extension theorem
Are EC-spaces AE(metrizable)?