On multiple positive ground state solutions for a mean curvature equation in Minkowski space

In this paper, we show how changes in the sign of nonlinearity leads to multiple radial ground state solutions of the mean curvature equation $ \nabla\cdot \Big[\frac{\nabla u}{\sqrt{1-|\nabla u|^2}}\Big] +\lambda f(u)=0\
$\text{in}$ \ $\mathbb{R}$^N $forsufficientlylarge$\lambda$with$N\geq 2$.