Three dimensional contact metric manifolds with Cotton solitons

Abstract

In this article we study a three dimensional contact metric manifold M 3 with Cotton solitons. We mainly consider two classes of contact metric manifolds admitting Cotton solitons. Firstly, we study a contact metric manifold with Qx 1⁄4 rx, where r is a smooth function on M constant along Reeb vector field x and prove that it is Sasakian or has constant sectional curvature 0 or 1 if the potential vector field of Cotton soliton is collinear with x or is a gradient vector field. Moreover, if r is constant we prove that such a contact metric manifold is Sasakian, flat or locally isometric to one of the following Lie groups: SUð2Þ or SOð3Þ if it admits a Cotton soliton with the potential vector field being orthogonal to Reeb vector field x. Secondly, it is proved that a ðk; m; nÞ-contact metric manifold admitting a Cotton soliton with the potential vector field being Reeb vector field is Sasakian. Furthermore, if the potential vector field is a gradient vector field, we prove that M is Sasakian, flat, a contact metric ð0; 4Þ-space or a contact metric ðk; 0Þ-space with k < 1 and k0 0. For the potential vector field being orthogonal to x, if n is constant we prove that M is either Sasakian, or a ðk; mÞ-contact metric space.