“…The oscillation problem for linear matrix Hamiltonian systems is that of finding explicit conditions on the coefficients of the system, providing its oscillation. This is an important problem of qualitative theory of differential equations and many works are devoted to it (see e.g., [1,3,5,6,[13][14][15][16][17][18] and cited works therein). Among them notice the following result, obtained by S. Kumari and S.Umamaheswaram Theorem 1.1 ([11, Theorem 2.1]).…”