Linear transformation and oscillation criteria for Hamiltonian systems (Q882006)

The author studies the linear Hamiltonian system \[ x'=A(t)x+B(t)u, \qquad u'=C(t)x-A^*(t)u, \] where \(A(t)\), \(B(t)\), \(C(t)\) are real \(n\times n\) matrix-valued functions, \(B\) and \(C\) are Hermitian, \(B\) is positive definite. Using a transformation which preserves oscillation properties of this system, the author derives new oscillation criteria from known oscillation criteria of other authors.