The Axiom of Cosymplectic Surfaces and W_4-manifolds / M. B. Banaru. // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2015. № 5. P. 34-37 [Moscow Univ. Mech. Bulletin. Vol. 72, N 2, 2017. P. 213-215].

An almost Hermitian manifold satisfies the cosymplectic t-hypersurfaces axiom if a cosymplectic hypersurface with the type number t passes through each its point. It is proved that if a W_4-manifold satisfies the cosymplectic t-hypersurfaces axiom with t\leq 1, then this manifold is Kählerian.

Key words: almost contact metric structure, cosymplectic structure, type number, hypersurface, W_4-manifold.