一类高阶微分方程第二特征值的上界

本文考虑形如（－１）ｔＤｔ（ｐ（ｘ）Ｄｔｙ）＝λ（－Ｄ２）ｒｙ，ｘ∈（ａ，ｂ），Ｄｋｙ（ａ）＝Ｄｋｙ（ｂ）＝０，ｋ＝０，１，２，…，ｔ－１｛的第二特征值λ２的上界问题，得到了定理１和定理２，其中定理１的估计系数与［ａ，ｂ］无关，定理２的结果在一定条件下比定理１的好．

On the Upper Bound of Second Eigenvalues for a Class of High Order Differential Equations

In this paper, we consider the upper bound of second eigenvalue about(-1)tDt(p(x)Dty)=λ(-D2)ry,x∈(a,b),Dky(a)=Dky(b)=0,k=0,1,2,…,t-1and obtained the Theorem 1 and Theorem 2. In some cases. The result of the Theorem 2 is better than the Theorem 1.