# Seminars & Colloquia Calendar

Topology/Geometry Seminar

#### Huai-Dong Cao (Lehigh University)

A gradient Ricci soliton is a complete Riemannian manifold (M, g), together with a smooth potential function f,  such that its Ricci tensor satisfies the equation  $$Ric + Hess f = lambda g$$, for some constant $$lambda$$.  Ricci solitons are important geometric objects because they are natural extensions of Einstein metrics and they model singularity formations in the Ricci flow.