Radial quasilinear elliptic problems with singular or vanishing potentials

In this paper we continue the work that we began in [6]. Given $ 1<p<N $, two measurable functions $ V\left(r \right)\geq 0 $ and $ K\left(r\right)> 0 $, and a continuous function $ A(r) >0 $ ($ r>0 $), we consider the quasilinear elliptic equation

$ -\mathrm{div}\left(A(|x| )|\nabla u|^{p-2} \nabla u\right) +V\left( \left| x\right| \right) |u|^{p-2}u = K(|x|) f(u) \quad \text{in }\mathbb{R}^{N}, $

where all the potentials $ A,V,K $ may be singular or vanishing, at the origin or at infinity. We find existence of nonnegative solutions by the application of variational methods, for which we need to study the compactness of the embedding of a suitable function space $ X $ into the sum of Lebesgue spaces $ L_{K}^{q_{1}}+L_{K}^{q_{2}} $. The nonlinearity has a double-power super $ p $-linear behavior, as $ f(t) = \min \left\{ t^{q_1 -1}, t^{q_2 -1} \right\} $ with $ q_1,q_2>p $ (recovering the power case if $ q_1 = q_2 $). With respect to [6], in the present paper we assume some more hypotheses on $ V $, and we are able to enlarge the set of values $ q_1 , q_2 $ for which we get existence results.