p(x)-Laplacian equations in RN with periodic data and nonperiodic perturbations

We consider the p(x)-Laplacian equations in RN with periodic data and nonperiodic perturbations being stationary at infinity, where the perturbations are done not only for the coefficients but also for the exponents. Using concentration–compactness principle, under appropriate assumptions, we prove the existence of ground state solutions vanishing at infinity for the equations. © 2007 Elsevier Inc. All rights reserved