On invariant submanifolds of almost \(\alpha\)-Kenmotsu manifolds (Q2822178)

The author introduces the notions of almost \(\alpha\)-Kenmotsu manifolds \(\tilde{M} \) and invariant submanifolds of almost \(\alpha\)-Kenmotsu manifolds \( M \). This is the main result of the paper under consideration. assume that \( M \) has a parallel second fundamental form. Then \( M \) is totally geodesic, i.e., the 2nd fundamental form \(\sigma \) of \( M \) is 0. Finally, a 3-dimensional example of almost \(\alpha\)-Kenmotsu manifold is given and studied in details.