Some characterizations of quasi-Einstein and twisted product manifolds

Abstract

We first consider quasi-Einstein manifolds with concircular generator vector field. Secondly, we get a result for a twisted product alternative to a result of Ponge- Reckziegel [13]. Then we study quasi-Einstein manifolds on twisted product structures. In particular, we examine the effect of the condition of quasi-Einstein on a twisted product to its factor manifolds. Also, we obtain some conditions for a twisted product satisfying the quasi-Einstein condition to be a warped or a direct product.