BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Ziquan Yang (Harvard University) DTSTART:20201223T030000Z DTEND:20201223T040000Z DTSTAMP:20260423T024021Z UID:POINTS/17 DESCRIPTION:Title: Finiteness and the Tate Conjecture in Codimension 2 for K3 Squares\nby Ziquan Yang (Harvard University) as part of POINTS - Peking Online Intern ational Number Theory Seminar\n\n\nAbstract\nTwo years ago\, via a refined CM lifting theory\, Ito-Ito-Koshikawa proved the Tate Conjecture for squa res of K3 surfaces over finite fields by reducing to Tate's theorem on the endomorphisms of abelian varieties. I will explain a different proof\, wh ich is based on a twisted version of Fourier-Mukai transforms between K3 s urfaces. In particular\, I do not use Tate's theorem after assuming some k nown properties of individual K3's. The main purpose of doing so is to ill ustrate Tate's insight on the connection between the Tate conjecture and t he positivity results in algebraic geometry for codimension 2 cycles\, thr ough some "geometry in cohomological degree 2".\n\nZoom ID = 613 5332 8443 \n\nPassword = 182269\n\nLink = https://zoom.com.cn/j/61353328443?pwd=eEpa NkpCdTBER3o1eFJER2NaS29qUT09\n LOCATION:https://researchseminars.org/talk/POINTS/17/ END:VEVENT END:VCALENDAR