【摘要】 本文研究了２ｎ阶实系数Ｅｕｌｅｒ微分算式生成的对称微分算子，得到了自伴Ｅｕｌｅｒ微分算子的谱是离散的充分必要条件．更多还原

【Abstract】 In this paper, 2nth order symmetric differential expressions with real valued coefficients are considered. Some results concerning the discreteness of spectrum of associated operators are obtained. Especially, the necessary and sufficient conditions are given which ensure that the spectrum of differential operators is discrete.更多还原