Stability and exact multiplicity of periodic solutions of Duffing equations with cubic nonlinearities

具有几何凹与凹非线性项的半正问题中的分岔曲线

Bifurcation Curves in Semipositone Problems with Geometrically Concave and Concave Nonlinearities

本文研究了定义在区间[-1,1]上且两端零边界条件的半正问题正解的精确重数与分岔曲线，允许函数f在零处右极限为负无穷，并纠正了早期作者的错误证明。

Multiplicity of clines for systems of indefinite differential equations arising from a multilocus population genetics model

We investigate sufficient conditions for the presence of coexistence states for different genotypes in a diploid diallelic population with dominance distributed on a heterogeneous habitat, considering also the interaction between genes at multiple loci. In mathematical terms, this corresponds to the study of the Neumann boundary value problem \begin{equation*} \begin{cases} \, p_{1}''+λ_{1} w_{1}(x,p_{2}) f_{1}(p_{1}) = 0, &\text{in $Ω$,} \, p_{2}''+λ_{2} w_{2}(x,p_{1}) f_{2}(p_{2}) = 0, &\text{in $Ω$,} \, p_{1}'=p_{2}'=0, &\text{on $\partialΩ$,} \end{cases} \end{equation*} where the coupling-…