# at.algebraic topology – How to determine (say up to conjugacy) elementary p-subgroups of a compact Lie group \$G\$?

Of course there are the $$p$$-subgroups of a maximal torus, and in the case $$G=PU_p$$, there is an interesting non toral elementary p-subgroup considered by Vistoli in this paper.

How many other cases are known? For example, how about $$G=PU_n$$ where $$n$$ is not a prime?