Solutions for fourth-order Kirchhoff type elliptic equations involving concave–convex nonlinearities in [formula omitted

Abstract

In this paper, we show the existence and multiplicity of solutions for the following fourth-order Kirchhoff type elliptic equations Δ2u−M(‖∇u‖22)Δu+V(x)u=f(x,u),x∈RN,where M(t):R→R is the Kirchhoff function, f(x,u)=λk(x,u)+h(x,u), λ≥0, k(x,u) is of sublinear growth and h(x,u) satisfies some general 3-superlinear growth conditions at infinity. We show the existence of at least one solution for above equations for λ=0. For λ>0 small enough, we obtain at least two nontrivial solutions. Furthermore, if f(x,u) is odd in u, we show that above equations possess infinitely many solutions for all λ≥0. Our theorems generalize some known results in the literatures even for λ=0 and our proof is based on the variational methods.