Solutions to Kirchhoff equations with critical exponent

In this paper, we study the following problems {Δ2u−M(∫Ω|∇u|2dx)Δu=λf(x,u)+|u|2∗−2uinΩu=Δu=0on∂Ω, where 2∗=2NN−4 is the critical exponent. Under some conditions on MM and ff, we prove the existence of nontrivial solutions by using variational methods.