Figure 3

The graph of \(\pmb{g_{k_{0}l_{0}}}\) . As the figure shows: When \(L_{k_{0}l_{0}}= 0 \), \(\Gamma_{1}\) is the graph of \(g_{k_{0}l_{0}}\); when \({L_{k_{0}l_{0}}< 0}\), \(\Gamma_{2}\) is the graph of \(g_{k_{0}l_{0}}\),Then the intersecting point of \(\Gamma_{i}\) (\(i=1,2\)) and β-axis is the first eigenvalue \(\beta_{k_{0}l_{0}}^{1}\). When \(L_{k_{0}l_{0}}=0\), the intersecting point of \(\Gamma_{1}\) and β-axis, \(\beta _{k_{0}l_{0}}^{1}= 0\), and \({(R,F)}\) is in curve L. When \(L_{k_{0}l_{0}}< 0\), the intersecting point of \(\Gamma_{2}\) and β-axis, \(\beta _{k_{0}l_{0}}^{1}> 0\), and \((R,F)\) is in region II.