Normalized ground states for a biharmonic Choquard equation with exponential critical growth

In this paper, we consider the normalized ground state solution for the following biharmonic Choquard type problem \begin{align*} \begin{split} \left{ \begin{array}{ll} Δ^2u-βΔu=λu+(I_μF(u))f(u), \quad\mbox{in}\ \ $\mathbb{R}$^4, \displaystyle\int_{$\mathbb{R}$^4}|u|^2dx=c^2,\quad u\in H^2($\mathbb{R}$^4), \end{array} \right. \end{split} \end{align} where $\beta \ge 0$, $c>0$, $\lambda \in \mathbb{R}$, $I_{\mu }=\frac{1}{\mathrm{\mid }x{\mathrm{\mid }}^{\mu }}$ with $\mu \in (0,4)$, $F(u)$ is the primitive function of $f(u)$, and $f$ is a continuous function with exponential critical growth in the sense of the Adams inequality. By using a minimax principle based on the homotopy stable family, we obtain that the above problem admits at least one ground state normalized solution.