Description
Date and Time: Monday, 22 June, 3pm to 4pm IST (joining time: 2.50pm IST)
Google Meet link: meet.google.com/gxv-jqky-vmy
Speaker: Krishna Hanumanthu
Affiliation: Chennai Mathematical Institute, Chennai
Title: Seshadri constants and rationality questions.
Abstract: Seshadri constants are a local measure of positivity of line
bundles and have many interesting applications. An important question is
whether Seshadri constants can be irrational. While the answer is expected
to be yes, currently we do not know any examples of irrational Seshadri
constants. In this talk, we will start with basics on Seshadri constants
and discuss important results and connections to well known questions. We
will then focus on rationality questions and exhibit irrational Seshadri
constants assuming some conjectures are true. The talk will be based on
two joint works, one with B. Harbourne and another with L. Farnik, J.
Huizenga, D. Schmitz and T. Szemberg. I will try to keep most of the talk
accessible to anyone with knowledge of basic algebraic geometry.