Let Ω,Ω’ ⊂ ℝⁿ be domains and let f: Ω → Ω’ be a homeomorphism. We show that if the composition operator maps the Sobolev-Lorentz space to for some q ≠ n then f must be a locally bilipschitz mapping.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm221-3-1,
author = {Stanislav Hencl and Lud\v ek Kleprl\'\i k and Jan Mal\'y},
title = {Composition operator and Sobolev-Lorentz spaces $WL^{n,q}$
},
journal = {Studia Mathematica},
volume = {223},
year = {2014},
pages = {197-208},
zbl = {1293.30050},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm221-3-1}
}
Stanislav Hencl; Luděk Kleprlík; Jan Malý. Composition operator and Sobolev-Lorentz spaces $WL^{n,q}$
. Studia Mathematica, Tome 223 (2014) pp. 197-208. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm221-3-1/