0
$\begingroup$

By saying distinct generator of a group $G$, is this saying that elements produced by the generator differ from elements produced by other generators?

The distinct generators of $G$ are the elements $g^r$ where $1 ≤ r < N $ and $gcd(r,N) = 1$. Thus, there are $ϕ(N)$ of them, where $ϕ$ is Euler’s phi function.

  • 0
    It would be better if you would include the whole context in your question. Then we could say for sure what it meant. Try quoting the sentence from your book that you are unsure of.2012-08-18
  • 0
    No, it is saying that these are distinct elements of the group, with the property that each of them, individually, generates the group.2012-08-18
  • 0
    @Andrew So when these groups are union-ed, it forms the group $G$?2012-08-18
  • 0
    @LucyZeo, you don't have to take a union. For example $\mathbb Z/4\mathbb Z = \langle 1\rangle$, but also $\mathbb Z/4\mathbb Z = \langle -1\rangle,$ and $-1 = 3\neq 1.$2012-08-18
  • 0
    what about the second question?2012-08-18
  • 0
    Nevermind. I'll separate the question.2012-08-18
  • 0
    The meaning of "distinct" is directly related to the fact that "generators" is plural; it makes no sense with the singular "generator". I will therefore edit the title; as it stands it is too confusing2012-08-18

1 Answers 1

1

I'm willing to bet that in this question, $G$ is a cyclic group of order $N$. To that end, I'm answering the question I think you meant to ask. If I'm wrong, please let me know. In the case where we have a cyclic group of order $N$, there are $\varphi(N)$ different generators, each of the form of the question.

To answer your question: No. When we say an element (say $g$) generates a group, it means that every element of the group is a power of that element (of the form $g^n$ for some $n$). If we were to say that the two elements $g,h$ generate $G$, often written $G = \langle g,h \rangle$, we mean that any element of $G$ can be written as $g^n h^m$ for some $m,n$.

So any two generators generate the same set of elements. By distinct generators, we mean that the two generators are different from eachother. For example, if we are working with the cyclic group of order $2$, there are two elements. We might call them $e$ (the identity) and $g$, so that $g^2 = e$. But $g^3$ also generates this group. But $g^3$ is the same as $g$, so they are not distinct even though the 'words' describing them are not the same.