sectional curvatures of plane sections containing the Reeb vector field different from 1 at
some point, is a (k, μ)-contact manifold. In particular for the standard contact metric structure
of the tangent sphere bundle the torsion tensor is η-parallel if and only if M is of constant
curvature, in which case its associated pseudo-Hermitian structure is CR-integrable. Next
we show that if the metric of a non-Sasakian (k, μ)-contact manifold (M, g) is a gradient Ricci …