Fix an algebraically closed field having characteristic and let be a simple algebraic group of classical type over Also let be maximal among closed connected subgroups of and consider a non-trivial -restricted irreducible rational -module In this thesis, we investigate the triples such that acts with exactly two composition factors on and see how it generalizes a question initially investigated by Dynkin in the s and then studied by numerous mathematicians. In particular, we study the natural embeddings of in both and and obtain results on the structure of certain Weyl modules.
Donna Testerman, Martin W. Liebeck