On the Topological and Uniform Structure of Diversities

• Main Author: Andrew Poelstra
• Format: Article
• Language: English
• Published: Hindawi Limited 2013-01-01
• Series: Journal of Function Spaces and Applications
• Online Access: http://dx.doi.org/10.1155/2013/675057

Diversities have recently been developed as multiway metrics admitting clear and useful notions of hyperconvexity and tight span. In this note, we consider the analytical properties of diversities, in particular the generalizations of uniform continuity, uniform convergence, Cauchy sequences, and completeness to diversities. We develop conformities, a diversity analogue of uniform spaces, which abstract these concepts in the metric case. We show that much of the theory of uniform spaces admits a natural analogue in this new structure; for example, conformities can be defined either axiomatically or in terms of uniformly continuous pseudodiversities. Just as diversities can be restricted to metrics, conformities can be restricted to uniformities. We find that these two notions of restriction, which are functors in the appropriate categories, are related by a natural transformation.