An optimal inequality on warped product semi-slant submanifolds of   nearly Kaehler manifolds
  Non-existence of warped product semi-slant submanifolds of Kaehler manifolds was proved in [17], it is interesting to find their existence. In this paper, we prove the existence of warped product semi-slant submanifolds of nearly Kaehler manifolds by a characterization. To this end we obtain an inequality for the squared norm of second fundamental form in terms of the warping function and the slant angle. The equality case is also discussed. 
Siraj Uddin, Falleh R. Al-Solamy, V.A. Khan and Cenap Ozel
math.DG