W^{k,p}(Ω) functions with k weak-derivatives in L^p. Sobolev embedding W^{k,p} ⊂ L^q for appropriate q (or C^m for k > n/p). Foundation of modern PDE theory.
W^{k,p}(Ω) functions with k weak-derivatives in L^p. Sobolev embedding W^{k,p} ⊂ L^q for appropriate q (or C^m for k > n/p). Foundation of modern PDE theory.