In: Advanced Math
Suppose that a group G acts on its power set P(G) by conjugation.
a) If H≤G, prove that the normalizer of N(H) is the largest subgroup K of G such that HEK. In particular, if G is finite show that |H| divides |N(H)|.
b) Show that H≤G⇐⇒every element B∈OH is a subgroup of G with B∼=H.
c) Prove that HEG⇐⇒|OH|= 1.