Almost Kenmotsu manifolds with a condition of \(\eta \)-parallelism
The authors study almost Kenmotsu manifolds \((M^{2n+1},\varphi,\xi,\eta,g) \) with \(\eta\)-parallel tensor \(h'=h\circ\varphi\), where \(2h=L_\xi\varphi\) and \(L\) denotes the Lie derivative. They show that \(\eta\)-parallelism of \(h'\) does not imply the CR-integrability of the structure. They also study the case that \(h'\) is \(\eta\)-parallel and the eigenvalue 0 of \(h\) has multiplicity \(>1\) .
scientific article; zbMATH DE number 5614681
scientific article