unicity of a 1-form












0












$begingroup$


I read somewhere that if the 1st cohomology group of a manifold is trivial, then it contains a 1-form that is unique up to an exact form.



Is this statement true?



Thank you!










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
    $endgroup$
    – Michael Albanese
    Dec 22 '18 at 0:20










  • $begingroup$
    Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
    $endgroup$
    – PerelMan
    Dec 22 '18 at 0:46








  • 1




    $begingroup$
    The point is that not every form is closed.
    $endgroup$
    – Aleksandar Milivojevic
    Jan 5 at 20:49
















0












$begingroup$


I read somewhere that if the 1st cohomology group of a manifold is trivial, then it contains a 1-form that is unique up to an exact form.



Is this statement true?



Thank you!










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
    $endgroup$
    – Michael Albanese
    Dec 22 '18 at 0:20










  • $begingroup$
    Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
    $endgroup$
    – PerelMan
    Dec 22 '18 at 0:46








  • 1




    $begingroup$
    The point is that not every form is closed.
    $endgroup$
    – Aleksandar Milivojevic
    Jan 5 at 20:49














0












0








0





$begingroup$


I read somewhere that if the 1st cohomology group of a manifold is trivial, then it contains a 1-form that is unique up to an exact form.



Is this statement true?



Thank you!










share|cite|improve this question









$endgroup$




I read somewhere that if the 1st cohomology group of a manifold is trivial, then it contains a 1-form that is unique up to an exact form.



Is this statement true?



Thank you!







differential-geometry






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 22 '18 at 0:03









PerelManPerelMan

760414




760414








  • 2




    $begingroup$
    If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
    $endgroup$
    – Michael Albanese
    Dec 22 '18 at 0:20










  • $begingroup$
    Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
    $endgroup$
    – PerelMan
    Dec 22 '18 at 0:46








  • 1




    $begingroup$
    The point is that not every form is closed.
    $endgroup$
    – Aleksandar Milivojevic
    Jan 5 at 20:49














  • 2




    $begingroup$
    If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
    $endgroup$
    – Michael Albanese
    Dec 22 '18 at 0:20










  • $begingroup$
    Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
    $endgroup$
    – PerelMan
    Dec 22 '18 at 0:46








  • 1




    $begingroup$
    The point is that not every form is closed.
    $endgroup$
    – Aleksandar Milivojevic
    Jan 5 at 20:49








2




2




$begingroup$
If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
$endgroup$
– Michael Albanese
Dec 22 '18 at 0:20




$begingroup$
If the first de Rham cohomology group is trivial, then every closed one-form is exact, but there are plenty of non-exact one-forms.
$endgroup$
– Michael Albanese
Dec 22 '18 at 0:20












$begingroup$
Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
$endgroup$
– PerelMan
Dec 22 '18 at 0:46






$begingroup$
Are you sure? if the first Rham cohomology group is trivial, then every closed form is exact, there can be no non-exact 1-form, since the Rham cohomology group is the quotient of closed forms over exact forms. Could you please give details?
$endgroup$
– PerelMan
Dec 22 '18 at 0:46






1




1




$begingroup$
The point is that not every form is closed.
$endgroup$
– Aleksandar Milivojevic
Jan 5 at 20:49




$begingroup$
The point is that not every form is closed.
$endgroup$
– Aleksandar Milivojevic
Jan 5 at 20:49










0






active

oldest

votes












Your Answer








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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3049020%2funicity-of-a-1-form%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
















draft saved

draft discarded




















































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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3049020%2funicity-of-a-1-form%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

Plaza Victoria

In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...