Flat Modules are Torsion-free
$begingroup$
Can anyone help me prove that a flat module is torsion-free? I’ve tried supposing is isn’t and then get the contradiction that it isn’t flat, but I’m not having any good results. Any suggestion is welcomed. Thanks.
abstract-algebra modules flatness
$endgroup$
add a comment |
$begingroup$
Can anyone help me prove that a flat module is torsion-free? I’ve tried supposing is isn’t and then get the contradiction that it isn’t flat, but I’m not having any good results. Any suggestion is welcomed. Thanks.
abstract-algebra modules flatness
$endgroup$
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13
add a comment |
$begingroup$
Can anyone help me prove that a flat module is torsion-free? I’ve tried supposing is isn’t and then get the contradiction that it isn’t flat, but I’m not having any good results. Any suggestion is welcomed. Thanks.
abstract-algebra modules flatness
$endgroup$
Can anyone help me prove that a flat module is torsion-free? I’ve tried supposing is isn’t and then get the contradiction that it isn’t flat, but I’m not having any good results. Any suggestion is welcomed. Thanks.
abstract-algebra modules flatness
abstract-algebra modules flatness
edited Jan 27 at 17:37
J. W. Tanner
3,8001320
3,8001320
asked Jan 27 at 16:41
Pedro SantosPedro Santos
1609
1609
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13
add a comment |
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3089790%2fflat-modules-are-torsion-free%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3089790%2fflat-modules-are-torsion-free%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
Consider, for a regular element $rin R$, the exact sequence $0to Rto Rto R/(r)to 0$
$endgroup$
– Max
Jan 27 at 17:55
$begingroup$
Ok yeah , that is going to be a s.e.s, i thought about doing something similiar but i dont see where i get what i want.
$endgroup$
– Pedro Santos
Jan 27 at 18:52
$begingroup$
Well you have a flat module and a short exact sequence, what can you do with it ?
$endgroup$
– Max
Jan 27 at 19:10
$begingroup$
Get another short exat sequence
$endgroup$
– Pedro Santos
Jan 27 at 19:13