Time: 15:15, Friday, 20/5/2022

Join Zoom Meeting

https://us02web.zoom.us/j/89603210669?pwd=dDJyYnJHd3A5WlR1cFFkRUlYa3loUT09

Meeting ID: 896 0321 0669

Passcode: 340252

Abstract: We shall review some of the general problems which are unsolved on rigid local systems and arithmetic $ell$-adic local systems. We‘ll report briefly on a proof (2018 with Michael Groechenig) of Simpson's integrality conjecture for {it cohomologically rigid local systems}. While all rigid local systems in dimension $1$ are cohomologically rigid (1996, Nick Katz), we did not know until last week of a single example in higher dimension which is rigid but not cohomologically rigid. We’ll present one series of examples (2022, joint with Johan de Jong and Michael Groechenig).

For general information of the AGEA seminar, please check out

https://sites.google.com/ncts.ntu.edu.tw/agea-seminar

or the mirror site

http://www.math.ntu.edu.tw/~jkchen/agea-seminar.html