Questions tagged [free-abelian-group]

This is for questions about abelian groups, each with a basis.

190 questions
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Basis of subgroup of a free abelian group

We have this theorem: ** Let $F$ be a free abelian group of rank $n$ and let $H$ be a subgroup of $F.$ There exists a basis $\{x_1,...,x_n\}$ of $F$ and integers $d_1,...,d_r > 0 $ such that • $di\vert d_{i+1}$ for $i = 1,...,r$ •…
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About order of Base of free abelian group

I am not sure about the connection between order of a base of free abelian group, to the order of the minimal generator set which generates the group. I would like to inherit the conclusion from linear algabra, says that a base holds the minimal…
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Free abelian group - exercise

Can someone please help me understand how to do this exercise? Show that multiplicative group of positive rationals is a free abelian group of countably infinite rank. So, I know i can begin with: Let Q be multiplicative group of positive…
user797618
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What is the free abelian group of an infinite set?

Given a set $S$, the free abelian group is defined as the set of formal sums of elements of $S$. Is this restricted to formal sums of a finite subset of elements of $S$? For example, is $S = \mathbb{R}$, then is $\sum_{z\in \mathbb{Z}}a_z z$ a…
Anon
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Conditions under which a union of free abelian groups is free

Let $(A_\nu)_{\nu<\mu}$ be an increasing sequence of free abelian groups such that for any limit ordinal $\lambda<\mu$, $A_\lambda=\bigcup_{\nu<\lambda}A_\nu$. Let $A=\bigcup_{\nu<\mu}A_\nu$. Let $\kappa$ be the cofinality of $\mu$. Assume that…
Tri
  • 387