Existence of solution for two classes of elliptic problems in RNRN with zero mass

In this paper we show the existence of a positive solution for the following class of elliptic equations−Δu=K(x)f(u)in RN where f is a continuous function with quasicritical growth and K is a nonnegative function verifying some conditions of two kinds. We analyze the problem with K asymptotically periodic, K periodic and K   belonging to some LrLr.