Existence and comparison theorems for eigenvalues of (k, n - k)-focal point and (k, n - k)-conjugate point problems are proved for a class of nth order linear differential equations for arbitrary n.

Boundary value problems (BVPs) and spectral analysis constitute fundamental areas in the study of differential equations. These topics not only underpin theoretical advances in mathematical analysis ...

In this work, we find the asymptotic formulas for the sum of the negative eigenvalues smaller than −ε (ε > 0) of a self-adjoint operator L defined by the following differential expression ℓ(y) = −(p(x ...