Three positive radial solutions for elliptic equations in a ball Original Research Article

In this work we deal with a class of second-order elliptic problems of the form View the MathML source−Δu=λk(|x|)f(u) in Ω, with non-homogeneous boundary condition u=a on ∂Ωu=a on ∂Ω where ΩΩ is the ball of radius R0R0 centered at origin, View the MathML sourceλ,a are positive parameters, f∈C([0,+∞),[0,+∞))f∈C([0,+∞),[0,+∞)) is an increasing function and k∈C([0,R0],[0,+∞))k∈C([0,R0],[0,+∞)) is not identically zero on any subinterval of [0,R0][0,R0]. We obtain via a fixed point theorem of cone expansion/compression type the existence of at least three positive radial solutions.