Einige Kennzeichnungen der homothetischen Abbildungen eines Riemannschjen Raumes unter den kreistreuen Abbildungen.
We prove that there is exactly one homothety class of invariant Einstein metrics in each space defined below.
In this paper we demonstrate the existence of Sasakian-Einstein structures on certain 2- connected rational homology 7-spheres. These appear to be the first non-regular examples of Sasakian-Einstein metrics on simply connected rational homology spheres. We also briefly describe the rational homology 7-spheres that admit regular positive Sasakian structures.