Monday, September 21st, 2026
Program Talks: Renzo Ricca
Time: 11:15 AM - 12:15 PM
Location: SCGP 313
Title: Topological Hydrodynamics
Speaker: Renzo Ricca
Title: Topological Hydrodynamics
Speaker: Renzo Ricca
Wednesday, September 23rd, 2026
Math Event: Algebraic Geometry Seminar: Jason Starr - New examples of rationally connected varieties and rationally simply connected varieties
Time: 4:00 PM - 5:00 PM
Location:
Speaker: Jason Starr
Abstract: For a family of smooth, projective varieties over a curve such that one fiber is a Fano complete intersection, does there exist a rational section of the family? In joint work with Zhiyu Tian we strengthen our earlier work with Ruhong Zong: there exist rational sections whenever the characteristic is at least as large as the degrees of the defining equations (of course this implies the characteristic zero case). We also prove new cases of "weak approximation", i.e., there exist enough rational sections to approximate power series / Laurent series sections to arbitrary order. For instance, this holds when the characteristic equals 0 and at least one fiber is "2-Fano": both the first and second graded pieces of the Chern character are positive.
Speaker: Jason Starr
Abstract: For a family of smooth, projective varieties over a curve such that one fiber is a Fano complete intersection, does there exist a rational section of the family? In joint work with Zhiyu Tian we strengthen our earlier work with Ruhong Zong: there exist rational sections whenever the characteristic is at least as large as the degrees of the defining equations (of course this implies the characteristic zero case). We also prove new cases of "weak approximation", i.e., there exist enough rational sections to approximate power series / Laurent series sections to arbitrary order. For instance, this holds when the characteristic equals 0 and at least one fiber is "2-Fano": both the first and second graded pieces of the Chern character are positive.