@article{Skrypnik_2020, title={Periodic Coulomb dynamics of two equal negative charges in the field of four equal positive fixed charges}, volume={72}, url={https://umj.imath.kiev.ua/index.php/umj/article/view/741}, DOI={10.37863/umzh.v72i10.741}, abstractNote={<p>UDC 517.9</p> <p>We found periodic solutions of the Coulomb $d$-dimensional $(d=1,2,3)$ equation of motion for two equal negative point charges in the field of four equal positive point charges fixed at vertices of a parallelepiped. <br>These systems possess an equilibrium configuration. <br>The periodic solutions are obtained with the help of Lyapunov’s central theorem.</p&gt;}, number={10}, journal={Ukrains’kyi Matematychnyi Zhurnal}, author={Skrypnik, W. I.}, year={2020}, month={Oct.}, pages={1432 - 1442} }