Three Radial Positive Solutions For Semilinear Elliptic Problems In R-N

This paper is concerned with the semilinear elliptic problem{-Delta u = lambda h(vertical bar x vertical bar)f(u) in R-N,u(x) > 0 in R-N,u -> 0 as vertical bar x vertical bar -> infinity,where lambda is a real parameter and h is a weight function which is positive. We show the existence of three radial positive solutions under suitable conditions on the nonlinearity. Proofs are mainly based on the bifurcation technique.