By means of variational structure and Z2 group index theory, we obtain multiple solutions of boundary value problems for second-order ordinary differential equations and lower bound estimate for number of the solutions.

• 摘要本文利用变分原理和Z2不变群指标研究了一类二阶常微分方程奇异边值问题的多重解，得出了这类解个数的下界估计。