三个高阶极限点型微分算子积的自伴性

On Self-adjointness of the Products of Three High-order Limit-point Differential Operators

设微分算式l(y)=y(2n)+qy,t∈[a,∞),满足lk(y)(k=1,2,3)均为极限点型.研究了由l(y)生成的三个微分算子Li(i=1,2,3)的乘积L3L2L1的自伴性问题,并获得其自伴的充分必要条件.

For the differential expression l（y） =- y^（2n）＋ qy, t ∈ [a, ∞）, under the assumption that l^k （k= 1,2,3） are limit-pointed, the author studies the self-adjointness of the product operator L3L2L1, which Li（i=1,2,3） are generated by l（y）,and the necessary and sufficient condition are obtained.