Existence and multiplicity of solutions for a critical Kirchhoff type elliptic equation with a logarithmic perturbation

Abstract: In this paper, we are interested in the following critical Kirchhoff type elliptic equation with a logarithmic perturbation \begin{equation}\label{eq0} \begin{cases} -\left(1+b\int_{\Omega}|\nabla{u}|^2\mathrm{d}x\right) \Delta{u}=\lambda u+\mu u\log{u^2}+|u|^{2^{*}-2}u, &x\in\Omega,\ u=0,&x\in\partial\Omega, \end{cases} \end{equation} where $\Omega$ is a bounded domain in $\mathbb{R}^{N}(N\geq3)$ with smooth boundary $\partial \Omega$, $b$, $\lambda$ and $\mu$ are parameters and $2^{*}=\frac{2N}{N-2}$ is the critical Sobolev exponent. The presence of a nonlocal term, together with a critical nonlinearity and a logarithmic term, prevents to apply in a straightforward way the classical critical point theory. Moreover, the geometry structure of the energy functional changes as the space dimension $N$ varies, which has a crucial influence on the existence of solutions to the problem. On the basis of some careful analysis on the structure of the energy functional, existence and (or) multiplicity results are obtained by using variational methods. More precisely, if $N=3$, problem (0.1) admits a local minimum solution, a ground state solution and a sequence of solutions with their $H_0^1(\Omega)$-norms converging to $0$. If $N=4$, the existence of infinitely many solutions is also obtained. When $N\geq5$, problem (0.1) admits a local minimum solution with negative energy. Sufficient conditions are also derived for the local minimum solution to be a ground state solution.