主讲人：吴大明 教授（美国Ohio大学）

时  间：6月23日（周四）16：00-17：00

地  点：数学科学学院 201 教室

备  注：摘要： In this talk I shall first recall the condition of nonnegative quadratic bisectional curvature, which was introduced by Yau, Zheng, and myself to construct smooth representatives for nef cohomology classes. The curvature condition is weaker than some known conditions such as nonnegative orthogonal bisectional curvature. I will survey some recent different proofs for our result. Then, I will discuss an ongoing joint work with Qun Li and Fangyang Zheng. We study constant rank theorems under the curvature condition, and construct a geometric example that satisfy our curvature condition but not other curvature conditions.