A generalized porous medium equation related to some singular quasilinear problems

In this paper we study the existence and nonexistence of solutions for a Dirichlet boundary value problem whose model is {−∑m=1∞amΔum=fin Ωu=0on ∂Ω, where ΩΩ is a bounded domain of RNRN, amam is a sequence of nonnegative real numbers, and ff is in Lq(Ω)Lq(Ω), q>N2.