Codice QDD196 Titolo Bach-flat gradient steady Ricci solitons Data 2015-02-26 Autore/i Cao, H.-D.; Catino, G.; Chen, Q.; Mantegazza, C.; Mazzieri, L. Link Download full text Pubblicato Calc. Var. Partial Differential Equations, 49 (2014) no. 1-2, 125-138 Abstract In this paper we prove that any n-dimensional (n>3) complete Bach-flat gradient steady Ricci solitons with positive Ricci curvature is isometric to the Bryant soliton. We also show that a three-dimensional gradient steady Ricci soliton with divergence-free Bach tensor is either flat or isometric to the Bryant soliton.