Question about order of an element

  • Thread starter Thread starter epr2008
  • Start date Start date
  • Tags Tags
    Element
epr2008
Messages
44
Reaction score
0
I think that I just noticed something that I probably should have noticed a lot earlier in my Abstract Algebra class:

If G is a group which contains some g of finite order, then by definition g^k=e for some integer k. Does this mean that each element of finite order in G can be written as the generator of some some cyclic subgroup of G?
 
Physics news on Phys.org
Every element of a group generates a cyclic subgroup of the larger group, and the order of the element doesn't need to be finite for the resulting subgroup to be cyclic. Cyclic just means that it's generated by one element.
 
##\textbf{Exercise 10}:## I came across the following solution online: Questions: 1. When the author states in "that ring (not sure if he is referring to ##R## or ##R/\mathfrak{p}##, but I am guessing the later) ##x_n x_{n+1}=0## for all odd $n$ and ##x_{n+1}## is invertible, so that ##x_n=0##" 2. How does ##x_nx_{n+1}=0## implies that ##x_{n+1}## is invertible and ##x_n=0##. I mean if the quotient ring ##R/\mathfrak{p}## is an integral domain, and ##x_{n+1}## is invertible then...
The following are taken from the two sources, 1) from this online page and the book An Introduction to Module Theory by: Ibrahim Assem, Flavio U. Coelho. In the Abelian Categories chapter in the module theory text on page 157, right after presenting IV.2.21 Definition, the authors states "Image and coimage may or may not exist, but if they do, then they are unique up to isomorphism (because so are kernels and cokernels). Also in the reference url page above, the authors present two...
When decomposing a representation ##\rho## of a finite group ##G## into irreducible representations, we can find the number of times the representation contains a particular irrep ##\rho_0## through the character inner product $$ \langle \chi, \chi_0\rangle = \frac{1}{|G|} \sum_{g\in G} \chi(g) \chi_0(g)^*$$ where ##\chi## and ##\chi_0## are the characters of ##\rho## and ##\rho_0##, respectively. Since all group elements in the same conjugacy class have the same characters, this may be...

Similar threads

Replies
3
Views
453
Replies
13
Views
589
Replies
7
Views
2K
Replies
2
Views
2K
Replies
14
Views
3K
Replies
6
Views
1K
Replies
3
Views
1K
Back
Top