BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Padmavathi Srinivasan (University of Georgia) DTSTART:20211202T233000Z DTEND:20211203T003000Z DTSTAMP:20260422T053944Z UID:SFUQNTAG/46 DESCRIPTION:Title: Some Galois cohomology classes arising from the fundamental group of a c urve\nby Padmavathi Srinivasan (University of Georgia) as part of SFU NT-AG seminar\n\n\nAbstract\nWe will first talk about the Ceresa class\, w hich is the image under a cycle class map of a canonical algebraic cycle a ssociated to a curve in its Jacobian. This class vanishes for all hyperell iptic curves and was expected to be nonvanishing for non-hyperelliptic cur ves. In joint work with Dean Bisogno\, Wanlin Li and Daniel Litt\, we cons truct a non-hyperelliptic genus 3 quotient of the Fricke-Macbeath curve wi th vanishing Ceresa class\, using the character theory of the automorphism group of the curve\, namely\, PSL_2(F_8). This will also include the tale of another explicit genus 3 curve studied by Schoen that was lost and the n found again!\n\nTime permitting\, we will also talk about some Galois co homology classes that obstruct the existence of rational points on curves\ , by obstructing splittings to natural exact sequences coming from the fun damental group of a curve. In joint work with Wanlin Li\, Daniel Litt and Nick Salter\, we use these obstruction classes to give a new proof of Grot hendieck’s section conjecture for the generic curve of genus g > 2. An a nalysis of the degeneration of these classes at the boundary of the moduli space of curves\, combined with a specialization argument lets us prove t he existence of infinitely many curves of each genus over p-adic fields an d number fields that satisfy the section conjecture.\n LOCATION:https://researchseminars.org/talk/SFUQNTAG/46/ END:VEVENT END:VCALENDAR