Groups of prime order structurally distinct?

In summary, the conversation discusses the properties of a group G of order p where p is prime. It is known that G is isomorphic to Zp and Cp, and as a cyclic group, all its elements are generators. The only subgroups of G are the trivial subgroup and G itself, and G is abelian. It is also mentioned that any nontrivial homomorphism from G to another group G' must be injective. The question arises whether for each prime p, there is only one structurally distinct group of order p. The answer is yes, as the fundamental theorem of finite abelian groups guarantees that any group of order p is isomorphic to Zp. It is also shown that two groups of order p
  • #1
dumbQuestion
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I have a question. If I have a group G of order p where p is prime, I know from the *fundamental theorem of finite abelian groups* that G is isomorphic to Zp (since p is the unique prime factorization of p, and I know this because G is finite order) also I know G is isomorphic to Cp (the pth roots of unity). I also know that G is cyclic and since its isomorphic to Zp I know that all of its elements are generators. Also we know that the only subgroups of G are the trivial subgroup and G itself. We know because G is cyclic, that it is abelian. These are the properties I can determine. [EDIT: Thought of another thing. any nontrivial homomorphism from h: G --> G' should be injective right because ker(h) should be trivial because ker(h) is a subgroup of G and we know G only has subgroups {e} and G itself, and if h is not trivial this means ker(h) must be {e} so its trivial meaning h is injective]But is it true that for each prime p, there is only one structurally distinct group (up to isomorphism)? Is there a theorem that indicates one way or another this fact?EDIT: Think I figured it out. FUndamental theorem of finite abelian groups gauranteeds that if G and G' are both groups of order p where p is prime, then G isomorphic to Zp and G' isomorphic to Zp so this means G isomorphic to G'. Since the selection of G and G' are arbitrary, this means for all G, G' of order p, p prime that G is isomorphic to G' so there is only one structurally distinct group of order p
 
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  • #2
dumbQuestion said:
But is it true that for each prime p, there is only one structurally distinct group (up to isomorphism)? Is there a theorem that indicates one way or another this fact?

If G is a group of order p, then define f:G → Zp by mapping a generator of G to 1. This produces an isomorphism.
 
  • #3
But this is showing that G and Zp are isomorphic, right? I'm curious about two groups of order p that are not isomorphic to each other.
 
  • #4
dumbQuestion said:
But this is showing that G and Zp are isomorphic, right? I'm curious about two groups of order p that are not isomorphic to each other.

Isomorphism is an equivalence relation. If both groups of order p are isomorphic to Zp, then they are isomorphic to each other.
 
  • #5
Yeah I see that now, I feel kind of stupid now for not seeing it before!
 

FAQ: Groups of prime order structurally distinct?

1. What does it mean for a group to have a prime order?

A group with a prime order means that the number of elements in the group is a prime number, which is a number that is only divisible by 1 and itself.

2. What is the significance of groups of prime order?

Groups of prime order are important in mathematics and in various applications, such as cryptography. They have unique properties that make them useful in solving certain problems.

3. What does it mean for groups of prime order to be structurally distinct?

Groups of prime order can be considered structurally distinct if they have different structures or properties despite having the same number of elements. In other words, they cannot be transformed into each other through a process of relabeling elements.

4. How many groups of prime order are there?

There is an infinite number of groups of prime order. This is because there are an infinite number of prime numbers, and each prime number can be the order of a unique group.

5. Can groups of prime order be isomorphic?

No, groups of prime order cannot be isomorphic. Isomorphic groups have the same structure and properties, but groups of prime order are structurally distinct, meaning they have different structures and properties.

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