The normal structure of unipotent subgroups in Lie-type groups and related questions. (Q951722)

The authors study the normal subgroup structure of the unipotent subgroup \(U\) of a Chevalley group (including the twisted types) generated by the root subgroups for the positive roots. In particular, they list all the maximal Abelian normal subgroups of such a \(U\). The theorems, whose statements alone occupy something like two thirds of this note, are very complex to state with many cases involving much notation. There are no proofs and little discussion. There are brief notes explaining the notation.