Thread: isomorphism

Hi,

Can someone please tell me a method for describing Aut(Cn) as a product of cyclic groups

e.g describe Aut(C30) as a product of cyclic groups.

Thanks.

Originally Posted by jedoob

Hi,

Can someone please tell me a method for describing Aut(Cn) as a product of cyclic groups

e.g describe Aut(C30) as a product of cyclic groups.

Thanks.

I never studied the automorphism group.
However, it seems to me that...

Aut(Z_n)
Has phi(n) elements and it is cyclic.
Hence,
Aut(Z_n) is isomorphic to Z_{phi(n)}.

I am assuming C_n means a cyclic group, right?