The Bohl transformation for second order linear differential systems (Q1262424)

The method of the Bohl transformation in the study of the properties of matrix solutions of the self-adjoint second order linear differential system \(X''+P(t)X=0\) is applied. P(t) is an \(n\times n\) Hermitian matrix with continuous complex valued elements of a real variable \(t\in [a,\infty)\). Some new criteria for oscillation of this system and criteria for the global existence of solutions of certain nonlinear system of differential equations are proved.