Fractional Schrödinger–Poisson system involving concave and convex nonlinearities

In this paper, we investigate the following fractional Schrödinger–Poisson system: \begin{cases}(-\Delta)^{s}u+V(x)u+\phi u=P(x)|u|^{p-2}u-Q(x)|u|^{q-2}u&\text{in }\mathbb{R}^{3},\\\ (-\Delta)^{s} \phi=u^{2}&\text{in }\mathbb{R}^{3},\end{cases} where 1<p<2<q<+\infty , (-\Delta)^{s} denotes the fractional Laplacian of order s\in(\frac{3}{4},1) , and V(x) , P(x) , and Q(x) are given functions satisfying certain conditions. We aim to establish the existence of infinitely many solutions for this system, considering nonlinearities P(x)|u|^{p-2}u and Q(x)|u|^{q-2}u with varying growth rates, including subcritical, critical, and supercritical cases.