Homomorphism from Z into a nonabelian group

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Discussion Overview

The discussion revolves around the existence of nontrivial homomorphisms from the group of integers Z into a nonabelian group. Participants explore specific examples and properties of such homomorphisms, particularly focusing on the dihedral group of order 6.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant asks for examples of homomorphisms f, g: Z-->W such that f(n)g(m) does not commute for some integers n and m.
  • Another participant identifies the dihedral group of order 6, D_3, as the smallest nonabelian group and notes that it contains elements from Z_2 and Z_3 that do not commute.
  • A further contribution explains that a homomorphism from Z into any group G is determined by the image of 1, stating that if f(1)=g, then f(n)=gn for any integer n, emphasizing the freedom in choosing f(1).
  • One participant expresses gratitude for the clarification provided by another participant.

Areas of Agreement / Disagreement

Participants do not reach a consensus on specific examples of nontrivial homomorphisms, and the discussion includes multiple perspectives on the properties of such mappings.

Contextual Notes

The discussion does not resolve the implications of choosing different elements in the nonabelian group for the homomorphisms, nor does it clarify the conditions under which the noncommutativity arises.

quasar987
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What would be an example of a (nontrivial) homomorphism from Z into a nonabelian group??

More specifically, I am looking for two homomorphisms f, g: Z-->W such that for some n,m in Z f(n)g(m) does not commute.
 
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Ah! I found out that the smallest nonabelian group is the diedral group of order 6, D_3. And from its multiplication table, we see that embedded in it is a copy of Z_2 and a copy of Z_3 that contain elements that do not commute.
 
A homomorphism from Z into any group G is completely specified by picking f(1), because if f(1)=g, then f(n)=gn. And you can pick f(1) to be any element of G that you want, basically because Z is a free group.
 
Thanks for that remark StatusX.
 

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