Existence of Nontrivial Solutions to a Critical Fourth-Order Kirchhoff Type Elliptic Equation

In this paper, a critical fourth-order Kirchhoff type elliptic equation with a subcritical perturbation is studied. The main feature of this problem is that it involves both a nonlocal coefficient and a critical term, which bring essential difficulty for the proof of the existence of weak solutions. When the dimension of the space is smaller than or equals to 7, the existence of weak solution is obtained by combining the Mountain Pass Lemma with some delicate estimate on the Talenti’s functions. When the dimension of the space is larger than or equals to 8, the above argument no longer works. By introducing an appropriate truncation on the nonlocal coefficient, it is shown that the problem admits a nontrivial solution under appropriate conditions on the parameter.