10-11【张鼎新】Betti numbers of affine varieties

发布时间:2024-09-19来源:几何与物理研究中心中文网页浏览次数:10

报告人:张鼎新(清华大学丘成桐数学科学中心)

时间:2024年10月11日 10:00-11:00

地点:物质科研楼C1124



Suppose V is a subspace of C^n, cut out by polynomial equations of degree ≤ d. Let B(V) be the sum of the compactly supported Betti numbers of V. In the 90s, Katz demonstrated that B(V) does not exceed Cd^(n+1) for some constant C depending only on n. Previously, Milnor and Thom had provided a less accurate upper bound of Cd^(2n). In this talk, I will explain how to deduce a sharper upper bound, B(V) ≤ Cd^n, using the characteristic p method. Time permitting, I will also discuss the relation of this bound with the Hodge theory of polynomial maps. This is a joint work with Daqing Wan.