BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Bianca Gouthier (MPIM Bonn) DTSTART:20251112T160000Z DTEND:20251112T170000Z DTSTAMP:20260418T064150Z UID:LNTS/178 DESCRIPTION:Title: I nfinitesimal rational actions on curves\nby Bianca Gouthier (MPIM Bonn ) as part of London number theory seminar\n\nLecture held in Imperial Coll ege London\, Room 139.\n\nAbstract\nFor any finite $k$-group scheme $G$ ac ting rationally on a $k$-variety $X$\, if the action is generically free t hen the dimension of $Lie (G)$ is upper bounded by the dimension of the va riety.\nThis inequality turns out to be also a sufficient condition for th e existence of such actions\, when $k$ is a perfect field of positive char acteristic and $G$ is infinitesimal commutative trigonalizable.\nIn this t alk\, we will specialize to the case in which $X$ is a curve. First\, we w ill give an explicit description of all the infinitesimal commutative unip otent group schemes $G$ with a generically free rational action on $X$ whe n $k$ is algebraically closed. We will then see how these actions can be c onstructed\, focusing on the case in which $G$ is the $p$-torsion of a sup ersingular elliptic curve.\n LOCATION:https://researchseminars.org/talk/LNTS/178/ END:VEVENT END:VCALENDAR