This paper deals with the obstacle problem for the infinity Laplacian. The main results are a characterization of the solution through comparison with cones that lie above the obstacle and the sharp -regularity of the solutions at the free boundary.
Julio D. Rossi, Eduardo V. Teixeira, José Miguel Urbano, Optimal regularity at the free boundary for the infinity obstacle problem. Interfaces Free Bound. 17 (2015), no. 3, pp. 381–398
DOI 10.4171/IFB/347