Nonlinear eigenvalue problems for a class of ordinary differential equations

originates in the works of Mirzov [17] and Elbert [5], who named these equations `half linear’. This theory extends various aspects of oscillation theory, such as the Picone identity [10], Sturm comparison theorem [16, 17], oscillation and nonoscillation criteria of Kneser type [16] and Hille type [14], and other oscillation criteria [3]. One branch of this research is the study of the eigenvalue problem