2nth order boundary value problems;
Eigenvalues;
Finite spectrum;
STURM-LIOUVILLE PROBLEMS;
D O I:
10.1016/j.aml.2014.10.003
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
For any even positive integer 2n and any positive integer m we construct a class of regular self-adjoint and non-self-adjoint boundary value problems whose spectrum consists of at most (2n 1)m + 1 eigenvalues. Our main result reduces to previously known results for the cases n = 1 and n = 2. In the self-adjoint case with separated boundary conditions this upper bound can be improved to n(m + 1). (C) 2014 Elsevier Ltd. All rights reserved.