3-Kenmotsu manifolds (Q2207035)

A \(3\)-Kenmotsu manifold, as defined by the author, is a manifold endowed with three Kenmotsu structures \((\phi_i, \eta, \xi, g)\) (\(i=1,2,3\)), such that \(\phi_1, \phi_2, \phi_3\) satisfy the quaternionic relations. After proving some properties of these structures, the author gives an example on an open set of \(\mathbb{ R}^5\).