A What is a free product of groups or vector space?

  • A
  • Thread starter Thread starter Heidi
  • Start date Start date
Heidi
Messages
420
Reaction score
40
Hi Pfs,
I do not succeed to handle free products of groups or vector spaces.
In the case of two vector spaces E and F the product (E,F) is the same thing that the free product E * F
I rad this article
https://en.wikipedia.org/wiki/Free_product
i would like to construct a free product in simple cases (say with groups of 2*2 matrices or somehthing
like that)
thanks
 
Physics news on Phys.org
What exactly is yout question?
 
The free product of two nontrivial groups is infinite. It's difficult to exhibit examples other than describe the generating process, which is outlined in your link, already.

It also doesn't matter how one labels the elements in the groups. For instance, we can have matrices ##A,B,C## and permutations ##\sigma,\rho,\tau##. In the free product we just have words that might look something like ##A\sigma B\rho\tau C ## and so on. There is nothing about matrices or mappings that stands out here.
 
Last edited:
I asked online questions about Proposition 2.1.1: The answer I got is the following: I have some questions about the answer I got. When the person answering says: ##1.## Is the map ##\mathfrak{q}\mapsto \mathfrak{q} A _\mathfrak{p}## from ##A\setminus \mathfrak{p}\to A_\mathfrak{p}##? But I don't understand what the author meant for the rest of the sentence in mathematical notation: ##2.## In the next statement where the author says: How is ##A\to...
The following are taken from the two sources, 1) from this online page and the book An Introduction to Module Theory by: Ibrahim Assem, Flavio U. Coelho. In the Abelian Categories chapter in the module theory text on page 157, right after presenting IV.2.21 Definition, the authors states "Image and coimage may or may not exist, but if they do, then they are unique up to isomorphism (because so are kernels and cokernels). Also in the reference url page above, the authors present two...
##\textbf{Exercise 10}:## I came across the following solution online: Questions: 1. When the author states in "that ring (not sure if he is referring to ##R## or ##R/\mathfrak{p}##, but I am guessing the later) ##x_n x_{n+1}=0## for all odd $n$ and ##x_{n+1}## is invertible, so that ##x_n=0##" 2. How does ##x_nx_{n+1}=0## implies that ##x_{n+1}## is invertible and ##x_n=0##. I mean if the quotient ring ##R/\mathfrak{p}## is an integral domain, and ##x_{n+1}## is invertible then...
Back
Top