Homogeneous Ricci solitons

作者：Jablonski Michael^*

来源：Journal fur die Reine und Angewandte Mathematik, 2015, 699(699): 159-182.

DOI：10.1515/crelle-2013-0044

In this work, we study metrics which are both homogeneous and Ricci soliton. If there exists a transitive solvable group of isometries on a Ricci soliton, we show that it is isometric to a solvsoliton. Moreover, unless the manifold is flat, it is necessarily simply-connected and diffeomorphic to R-n.
In the general case, we prove that homogeneous Ricci solitons must be semi-algebraic Ricci solitons in the sense that they evolve under the Ricci flow by dilation and pullback by automorphisms of the isometry group. In the special case that there exists a transitive semi-simple group of isometries on a Ricci soliton, we show that such a space is in fact Einstein. In the compact case, we produce new proof that Ricci solitons are necessarily Einstein.
Lastly, we characterize solvable Lie groups which admit Ricci soliton metrics.

• 出版日期2015-2