On the integral characterization of principal solutions for half-linear ODE

摘要

We discuss a new integral characterization of principal solutions for half-linear differential equations, introduced in the recent paper of S. Fisnarova and R. Marik, Nonlinear Anal. 74 (2011), 6427-6433. We study this characterization in the framework of the existing results and we show when this new integral characterization with a parameter $lpha$ is equivalent with two extremal cases of the integral characterization used in the literature. We illustrate our results on the Euler and Riemann-Weber differential equations.