Factorisation of a map of modules
$begingroup$
Suppose you have a ring $A$, $B$ with and an $A$-module $M$. Suppose the projection $q:Arightarrow B$ is surjective, and that there's a map $f:Arightarrow M$. Under what assumptions and why does $f$ factor through a map $Brightarrow M$?
$$
newcommand{ra}[1]{!!!!!!!!!!!!xrightarrow{quad#1quad}!!!!!!!!}
newcommand{da}[1]{leftdownarrow{scriptstyle#1}vphantom{displaystyleint_0^1}right.}
%
begin{array}{lllllll}
A & ra{f} & M \
da{q} & & \
B & \
end{array}
$$
Sorry for the shitty diagram, but basically the question is when is there a unique arrow from $B$ to $M$ that makes the diagram commute.
abstract-algebra modules
$endgroup$
add a comment |
$begingroup$
Suppose you have a ring $A$, $B$ with and an $A$-module $M$. Suppose the projection $q:Arightarrow B$ is surjective, and that there's a map $f:Arightarrow M$. Under what assumptions and why does $f$ factor through a map $Brightarrow M$?
$$
newcommand{ra}[1]{!!!!!!!!!!!!xrightarrow{quad#1quad}!!!!!!!!}
newcommand{da}[1]{leftdownarrow{scriptstyle#1}vphantom{displaystyleint_0^1}right.}
%
begin{array}{lllllll}
A & ra{f} & M \
da{q} & & \
B & \
end{array}
$$
Sorry for the shitty diagram, but basically the question is when is there a unique arrow from $B$ to $M$ that makes the diagram commute.
abstract-algebra modules
$endgroup$
1
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07
add a comment |
$begingroup$
Suppose you have a ring $A$, $B$ with and an $A$-module $M$. Suppose the projection $q:Arightarrow B$ is surjective, and that there's a map $f:Arightarrow M$. Under what assumptions and why does $f$ factor through a map $Brightarrow M$?
$$
newcommand{ra}[1]{!!!!!!!!!!!!xrightarrow{quad#1quad}!!!!!!!!}
newcommand{da}[1]{leftdownarrow{scriptstyle#1}vphantom{displaystyleint_0^1}right.}
%
begin{array}{lllllll}
A & ra{f} & M \
da{q} & & \
B & \
end{array}
$$
Sorry for the shitty diagram, but basically the question is when is there a unique arrow from $B$ to $M$ that makes the diagram commute.
abstract-algebra modules
$endgroup$
Suppose you have a ring $A$, $B$ with and an $A$-module $M$. Suppose the projection $q:Arightarrow B$ is surjective, and that there's a map $f:Arightarrow M$. Under what assumptions and why does $f$ factor through a map $Brightarrow M$?
$$
newcommand{ra}[1]{!!!!!!!!!!!!xrightarrow{quad#1quad}!!!!!!!!}
newcommand{da}[1]{leftdownarrow{scriptstyle#1}vphantom{displaystyleint_0^1}right.}
%
begin{array}{lllllll}
A & ra{f} & M \
da{q} & & \
B & \
end{array}
$$
Sorry for the shitty diagram, but basically the question is when is there a unique arrow from $B$ to $M$ that makes the diagram commute.
abstract-algebra modules
abstract-algebra modules
asked Jan 20 at 12:49
DalamarDalamar
465410
465410
1
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07
add a comment |
1
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07
1
1
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07
add a comment |
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1
$begingroup$
What is $q$ exactly? A ring homomorphism? And what is $B$?
$endgroup$
– Randall
Jan 20 at 12:51
$begingroup$
Yes. You can take even B to be just a quotient ring A/I with I an ideal of A
$endgroup$
– Dalamar
Jan 20 at 13:07