From exceptional sets to non-free sections

Abstract: Manin’s conjecture is a conjectural asymptotic formula for the counting function of rational points on Fano varieties over global fields. Mainly with Brian Lehmann, I have been studying exceptional sets arising in this conjecture. In this talk I would like to discuss my joint work with Brian Lehmann and Akash Sengupta on birational geometry of exceptional sets, then I will discuss applications of this study to understand the geometry of moduli spaces of sections on Fano fibrations which is joint work with Brian Lehmann and Eric Riedl.

algebraic geometrynumber theory

Audience: researchers in the topic

SFU NT-AG seminar

Series comments: The Number Theory and Algebraic Geometry (NT-AG) seminar is a research seminar dedicated to topics related to number theory and algebraic geometry hosted by the NT-AG group (Nils Bruin, Imin Chen, Stephen Choi, Katrina Honigs, Nathan Ilten, Marni Mishna).

We acknowledge the support of PIMS, NSERC, and SFU.

For Fall 2025, the organizers are Katrina Honigs and Peter McDonald.

We normally meet in-person in the indicated room. For online editions, we use Zoom and distribute the link through the mailing list. If you wish to be put on the mailing list, please subscribe to ntag-external using lists.sfu.ca