Ground state solutions for magnetic Schrödinger equations with polynomial growth

In this article, we investigate the following nonlinear magnetic Schr & ouml;dinger equations: ( - i del + A ( x ) ) 2 u + V ( x ) u = f 1 ( x , divided by v divided by 2 ) v , ( - i del + A ( x ) ) 2 v + V ( x ) v = f 2 ( x , divided by u divided by 2 ) u , \left\{\begin{array}{l}{\left(-i\nabla +A\left(x))}<^>{2}u+V\left(x)u={f}_{1}\left(x,{| v| }<^>{2})v,\\ {\left(-i\nabla +A\left(x))}<^>{2}v+V\left(x)v={f}_{2}\left(x,{| u| }<^>{2})u,\end{array}\right. where V V is the electric potential and A A is the magnetic potential. Assuming that the nonlinear function f i ( i = 1 , 2 ) {f}_{i}\left(i=1,2) satisfies three types of polynomial growth assumptions: super-quadratic, asymptotically quadratic, and local super-quadratic at divided by x divided by -> infinity | x| \to \infty , we prove the existence of the Nehari-Pankov type ground state solutions using critical point theory together with the non-Nehari manifold method. The resulting problem engages two major difficulties: the first one is that the associated functional is strongly indefinite, and the second lies in verifying the link geometry and showing the boundedness of Cerami sequences. Our results extend and complement the present ones in the literature.