A p(x)-version of Diaz-Saa Inequality and some applications

The main result of this work is a new extension of the well known inequality by Diaz and Saa which, in our case, involves an anisotropic operator, such as the p(x)-Laplacian. Our present extension of this inequality enables us to establish several new results on the uniqueness of solutions and comparison principles for some anisotropic quasilinear elliptic equations. Our proofs take advantage of certain convexity properties of the energy functional associated with the p(x)-Laplacian.