It is shown that the hyperspace (resp. ) of non-empty closed (resp. closed and bounded) subsets of a metric space (X,d) is homeomorphic to ℓ₂ if and only if the completion X̅ of X is connected and locally connected, X is topologically complete and nowhere locally compact, and each subset (resp. each bounded subset) of X is totally bounded.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm113-2-4,
author = {T. Banakh and R. Voytsitskyy},
title = {Characterizing metric spaces whose hyperspaces are homeomorphic to l2},
journal = {Colloquium Mathematicae},
volume = {111},
year = {2008},
pages = {223-229},
zbl = {1155.54011},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm113-2-4}
}
T. Banakh; R. Voytsitskyy. Characterizing metric spaces whose hyperspaces are homeomorphic to ℓ₂. Colloquium Mathematicae, Tome 111 (2008) pp. 223-229. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm113-2-4/