Under certain assumptions, we characterize the almost $\eta$-Einstein, $\eta$-Ricci and $\eta$-Yamabe solitons on a pseudo-Riemannian manifold when the potential vector field of the soliton is infinitezimal harmonic or torse-forming. Moreover, in the second case, if the manifold is Ricci symmetric of constant scalar curvature, then the soliton is completely determined.
"Some Geometrical Aspects of Einstein, Ricci and Yamabe Solitons." J. Geom. Symmetry Phys. 52 17 - 26, 2019. https://doi.org/10.7546/jgsp-52-2019-17-26