Certain Curvature Conditions on Kenmotsu Manifolds and - η -Ricci Solitons.

The present paper deals with the investigations of a Kenmotsu manifold satisfying certain curvature conditions endowed with - η -Ricci solitons. First we find some necessary conditions for such a manifold to be φ -Einstein. Then, we study the notion of - η -Ricci soliton on this manifold and prove some significant results related to this notion. Finally, we construct a nontrivial example of three-dimensional Kenmotsu manifolds to verify some of our results. [ABSTRACT FROM AUTHOR]