Classifying Finite Abelian Groups

  • Thread starter Thread starter Kalinka35
  • Start date Start date
  • Tags Tags
    Finite Groups
Click For Summary
To classify the different isomorphism classes of abelian groups of order 1800, one can start with the prime factorization 1800 = 2^3 * 3^2 * 5^2. The classification theorem for finitely generated abelian groups provides a framework to determine the structure without needing to list each group individually. The discussion highlights the necessity of recognizing subgroups of orders 8, 9, and 25, which are guaranteed by the classification theorem. Concerns about the applicability of the Sylow theorems are noted, but they are deemed unnecessary for this classification task. Ultimately, the classification theorem suffices to identify all relevant subgroup structures.
Kalinka35
Messages
48
Reaction score
0

Homework Statement


Count and describe the different isomorphism classes of abelian groups of order 1800. I don't need to list the group individually, but I need to give some sort of justification.

Homework Equations


The Attempt at a Solution


I'm using the theorem to classify finitely generated abelian groups,
As always we will have Z_1800 to begin with.
Also we know 1800=23(32)(52).

But how do I count all of the possibilities?
 
Last edited:
Physics news on Phys.org
Why don't you start listing them individually? Maybe that will jog your imagination enough to figure out how to count them without listing them.
 
I've counted all the ones that you get by using the classification theorem for finite abelian groups but a problem I've encountered is using the information given by the Sylow theorems as none of the groups from the first theorem contain the necessary subgroups.
What I've gathered is that there must be at least one subgroup of order 8, 9, and 25 and there a bunch of possibilities for how many for all of them. The numbers just don't really add up right. Any ideas how to approach this?
 
You don't need the Sylow theorems. You have a complete classification theorem for abelian groups. That's all you need. That certainly gives you subgroups of order 8, 9 and 25. And several other orders besides. I'm not sure what you are fretting about. Which structure from the classification theorem doesn't give you these?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
5
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K