We study imbeddings of the Sobolev space : = u: Ω → ℝ with < ∞ when |α| ≤ m, in which Ω is a bounded Lipschitz domain in ℝⁿ, ϱ is a rearrangement-invariant (r.i.) norm and 1 ≤ m ≤ n - 1. For such a space we have shown there exist r.i. norms, and , that are optimal with respect to the inclusions . General formulas for and are obtained using the -method of interpolation. These lead to explicit expressions when ϱ is a Lorentz Gamma norm or an Orlicz norm.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm206-2-1, author = {Ron Kerman and Lubo\v s Pick}, title = {Explicit formulas for optimal rearrangement-invariant norms in Sobolev imbedding inequalities}, journal = {Studia Mathematica}, volume = {204}, year = {2011}, pages = {97-119}, zbl = {1238.46026}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm206-2-1} }
Ron Kerman; Luboš Pick. Explicit formulas for optimal rearrangement-invariant norms in Sobolev imbedding inequalities. Studia Mathematica, Tome 204 (2011) pp. 97-119. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm206-2-1/