  We prove a sharp dimensionless weighted estimate of the Riesz vector on a
Riemannian manifold with non-negative Bakry-Emery curvature. The proof is by
the method of Bellman functions, where the explicit expression of a Bellman
function of six variables is essential. Notice that our estimate is terms of
the Poisson characteristic of the weight includes the case of the Gauss space
as well as other spaces that are not necessarily of homogeneous type.
