(a) Let G be a finite abelian group and p prime with p | | G...
(a) Let G be a finite abelian group and p prime with p | | G |.
Show that there is only one p - Sylow subgroup of G. b) Find all p
- Sylow subgroups of (Z2500, +)
Theorem 2.1. Cauchy’s Theorem: Abelian Case: Let G be a finite
abelian group and p be a prime such that p divides the order of G
then G has an element of order p.
Problem 2.1. Prove this theorem.
Throughout this question, let G be a finite group, let p be a
prime, and suppose that H ≤ G is such that [G : H] = p.
Let G act on the set of left cosets of H in G by left
multiplication (i.e., g · aH = (ga)H). Let K be the set of elements
of G that fix every coset under this action; that is,
K = {g ∈ G : (∀a ∈ G) g · aH...
Let G be an abelian group and K is a subset of G.
if K is a subgroup of G , show that G is finitely generated if
and only if both K and G/K are finitely generated.
Let G be a group of order p
am where p is a prime not dividing m. Show the following
1. Sylow p-subgroups of G exist; i.e. Sylp(G) 6= ∅.
2. If P ∈ Sylp(G) and Q is any p-subgroup of G, then there exists g
∈ G such that Q 6
gP g−1
; i.e. Q is contained in some conjugate of P. In particular, any
two Sylow p-
subgroups of G are conjugate in G.
3. np ≡...
Let (G,+) be an abelian group and U a subgroup of G. Prove that
G is the direct product of U and V (where V a subgroup of G) if
only if there is a homomorphism f : G → U with f|U =
IdU
Let
G be a finite group and H a subgroup of G. Let a be an element of G
and aH = {ah : h is an element of H} be a left coset of H. If b is
an element of G as well and the intersection of aH bH is non-empty
then aH and bH contain the same number of elements in G. Thus
conclude that the number of elements in H, o(H), divides the number
of elements...
Let G be an abelian group.
(a) If H = {x ∈ G| |x| is odd}, prove that H is a subgroup of G.
(b) If K = {x ∈ G| |x| = 1 or is even}, must K be a subgroup of G?
(Give a proof or counterexample.)