BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Between the sheets: rigid nilpotent elements in modular Lie algebr
 as - David Stewart (University of Newcastle upon Tyne)
DTSTART:20200128T144500Z
DTEND:20200128T153500Z
UID:TALK137908@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:(Joint with Sasha Premet) Let G be a reductive algebraic group
  over an algebraically closed field. Lusztig and Spaltenstein provided a m
 ethod for inducing a nilpotent orbit from a Levi subgroup to the group G. 
 Any orbit not obtained from a proper Levi subgroup is called rigid. These 
 were classified by Kempken (for G classical) and Elashvili (for G exceptio
 nal). The latter was double-checked computationally by De Graaf. It turns 
 out that this classification remains valid in characteristic p. I will exp
 lain the proof of this\, obtained by extending the Borho-Kraft description
  of the sheets of the Lie algebra to positive characteristic and supported
  by a few computer calculations.
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR