For complete gradient Ricci solitons we state necessary conditions for a non-trivial soliton structure in terms of intrinsic curvature invariants.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm141-1-11, author = {Udo Simon}, title = {Complete gradient Ricci solitons}, journal = {Colloquium Mathematicae}, volume = {139}, year = {2015}, pages = {125-141}, zbl = {1330.53050}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm141-1-11} }
Udo Simon. Complete gradient Ricci solitons. Colloquium Mathematicae, Tome 139 (2015) pp. 125-141. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm141-1-11/