46.[Gaetz2018a]*Conj. 1.6
Let G:{e}=G0⊂G1⊂G2⊂⋯
be a tower of groups and let r∈Z>0.
Define P to be the splitting diagram of the representations of the
tower of groups, with weights that are the multiplicities of the
splittings.
The tower is r-dual if P is a self-dual
graded graph with differential degree r.
The tower is r-differential if the tower is r-dual and the
weights of P are all 1, it is a differential poset.
Show that:
(a) If G is r-differential then
P(G)≅Y⊗r and there exists an abelian
group A of order r, not depending on n, such that
Gn≅A≀Sn for all n≥0.
(b) If G is r-dual then
P(G)≅(d1Y)×⋯×(dkY) for
some d1,…,dk and there exists a group H of order r, not depending
on n, such that Gn≅H≀Sn for all n≥0.