Nonlinear Potential Theory and Weighted Sobolev Spaces The book systematically develops the nonlinear potential theory connected with the weighted Sobolev spaces where the weight usually belongs to Muckenhoupts class of Ap weights. These spaces occur as solutions spaces for degenerate elliptic partial differential equations. The Sobolev space theory covers results concerning approximation extension and interpolation Sobolev and Poincaré inequalities Mazya type embedding theorems and isoperimetric inequalities. In the chapter devoted to potential theory several weighted capacities are investigated. Moreover Kellogg lemmas are established for various concepts of thinness. Applications of potential theory to weighted Sobolev spaces include quasi continuity of Sobolev functions Poincaré inequalities and spectral synthesis theorems