\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
By studying the central force problem in the framework of
de-Broglie--Bohm theory, we observe that the perihelion precession
of planets may be understood as the effect of the quantum
potential. In fact, we show that there is a specific solution to
de-Broglie--Bohm equations, in which the radial dependence and the
sign of the quantum potential is exactly what is needed for the
perihelion precession. The free parameters can be chosen such that
the correct value of precession is obtained.
\end{document}