Resumen de Non-negative Ricci curvature on closed manifolds under Ricci flow

Davi Máximo

• In this short paper we show that non-negative Ricci curvature is not preserved under Ricci flow for closed manifolds of dimensions four and above, strengthening a previous result of Knopf for complete non-compact manifolds of bounded curvature. This brings down to four dimensions a similar result Böhm and Wilking have for dimensions twelve and above. Moreover, the manifolds constructed here are manifolds and relate to a question raised by Xiuxiong Chen.