A note on discontinuous problem with a free boundary

Authors

Department of Mathematics, Faculty of Science, University of Tlemcen, B.P. 119, Tlemcen 13000, Algeria

Abstract

We study a nonlinear elliptic problem with discontinuous nonlinearity ðPÞ Du ¼ fðuÞHðl  uÞ in X;
u ¼0 on @X;  where H is the Heaviside’s unit function, f, h are given functions and l is a positive real parameter.
We prove the existence of a unique solution and characterize the corresponding free boundary. Our methods relies on variational inequality approach combining with fixed point arguments.

Keywords