Here is a list of articles in the category Functional subgroups of the Computing portal that unifies foundations of mathematics and computations using computers. Given a group, there are some subgroups of interest that can be defined uniquely and functionally in terms of [math]\displaystyle{ G }[/math], such as the center, commutator, etc. These should be invariant under isomorphisms, that is, any isomorphism on the groups, must induce a corresponding isomorphism on the subgroups. Hence, such subgroups are invariant under automorphisms, and are always characteristic subgroups.
The following 9 pages are in this category, out of 9 total.