Existence results for semilinear elliptical hemivariational inequalities

We are interested in studying the existence of solutions to an elliptical hemivariational inequality, depending on a real parameter λλ. The main tool in the proof of our results is a critical point theorem recently established. We obtain the existence of solution through a direct method, both with a changing sign nonlinearity of the kind p(x)f(ξ)p(x)f(ξ) and in the classical one P(x,ξ)P(x,ξ) too.