Lower Bound For The Ratios Of Eigenvalues Of Schrödinger Equations With Nonpositive Single-Barrier Potentials

Jamel Ben Amara, Hedhly Jihed

Horváth and Kiss [Proc. Amer. Math. Soc., 2005] proved the upper bound estimate $\frac{{\lambda }_n}{{\lambda }_m}\le \frac{n^2}{m^2}$ $(n>m\ge 1)$ for Dirichlet eigenvalue ratios of the…