We define a Sobolev space by means of a generalized Poincaré inequality and relate it to a corresponding space based on upper gradients.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm181-1-1, author = {Toni Heikkinen and Pekka Koskela and Heli Tuominen}, title = {Sobolev-type spaces from generalized Poincar\'e inequalities}, journal = {Studia Mathematica}, volume = {178}, year = {2007}, pages = {1-16}, zbl = {1129.46026}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm181-1-1} }
Toni Heikkinen; Pekka Koskela; Heli Tuominen. Sobolev-type spaces from generalized Poincaré inequalities. Studia Mathematica, Tome 178 (2007) pp. 1-16. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm181-1-1/