Finite-Dimensional Pointed Hopf Algebras Over Finite Simple Groups of Lie Type IV. Unipotent Classes in Chevalley and Steinberg Groups

摘要

We show that all unipotent classes in finite simple Chevalley or Steinberg groups, different from PSLn(q) and PSp(2n)(q), collapse (i.e. are never the support of a finite-dimensional Nichols algebra), with a possible exception on one class of involutions in PSUn(2(m)).