A note on almost co-Kähler manifolds.

We characterize almost co-Kähler manifolds with gradient Yamabe, gradient Einstein and quasi-Yamabe solitons. It is proved that if the metric of a (κ , μ) -almost co-Kähler manifold M 2 n + 1 is a gradient Yamabe soliton, then M 2 n + 1 is either K -almost co-Kähler or N (κ) -almost co-Kähler or the metric of M 2 n + 1 is a trivial gradient Yamabe soliton. A (κ , μ) -almost co-Kähler manifold with gradient Einstein soliton is K -almost co-Kähler. Finally, it is shown that an almost co-Kähler manifold admitting a quasi-Yamabe soliton, whose soliton vector is pointwise collinear with the Reeb vector field of the manifold, is K -almost co-Kähler. Consequently, some results of almost co-Kähler manifolds are deduced. [ABSTRACT FROM AUTHOR]