On the regularity of solutions of one-dimensional variational obstacle problems

Abstract

AbstractWe study the regularity of solutions of one-dimensional variational obstacle problems in {W^{1,1}} when the Lagrangian is locally Hölder continuous and globally elliptic. In the spirit of the work of Sychev [5, 6, 7], a direct method is presented for investigating such regularity problems with obstacles. This consists of introducing a general subclass {\mathcal{L}} of {W^{1,1}}, related in a certain way to one-dimensional variational obstacle problems, such that every function of {\mathcal{L}} has Tonelli’s partial regularity, and then to prove that, depending on the regularity of the obstacles, solutions of corresponding variational problems belong to {\mathcal{L}}. As an application of this direct method, we prove that if the obstacles are {C^{1,\sigma}}, then every Sobolev solution has Tonelli’s partial regularity.