فهرست نشریات علمی دسترسی آزاد ایران

In this article‎, ‎a new definition‎, ‎called $ \varphi $-normal‎, ‎is introduced‎, ‎which is a generalization of normal condition on almost contact manifolds‎. ‎Then some examples of $ \varphi $-normal almost contact manifolds that are not normal are presented‎, ‎and a sufficient and necessary condition for equivalence of these two definitions in 3-dimensional almost contact manifolds is provided‎. ‎In the end‎, ‎it is proven that a $ \varphi$-normal contact metric manifold is a Sasakian manifold‎.