Hyperspace convergences, bornologies and geometric set functionals

Abstract

For a bornology $\mathcal{S}$ of subsets of a metric space $(X,d)$, we consider the following unified approaches of hyperspace convergence: convergence induced through uniform convergence of distance functionals ($τ_{\mathcal{S},d}$-convergence); bornological convergence, and the weak convergence induced by a family of gap and excess functionals. An interesting problem regarding these convergences is to investigate when any two of them are equivalent. In this article, we investigate the relation of $τ_{\mathcal{S},d}$-convergence with the other two convergences, which is not completely transparent. As a main tool for our investigation, we use the idea of pointwise enlargement of a set by a positive Lipschitz function. As applications of our results, we provide new proofs of some known results about Attouch-Wets convergence.