Spike Solutions for a Class of Singularly Perturbed Quasilinear Elliptic Equations

By means of a penalization scheme due to del Pino and Felmer, we prove the existence of single–peaked solutions for a class of singularly perturbed quasilinear elliptic equations associated with functionals which lack of smoothness. We don’t require neither uniqueness assumptions on the limiting autonomous equation nor monotonicity conditions on the nonlinearity. Compared with the semilinear case some difficulties arise and the study of concentration of the solutions needs a somewhat involved analysis in which the Pucci–Serrin variational identity plays an important role.