Is there a substitution which transforms every Fermat curve into an elliptic curve?












9












$begingroup$


A Fermat Curve of degree $n$ is the set of solutions to $x^n+y^n=z^n$, $x,y,zin mathbb R$. In this question, the OP provides a substitution which relates a Fermat Curve of degree $n=3,4$ to two different elliptic curves. To transform the Fermat Curve of degree $3$, the substitutions
$$ a=frac{12z}{x+y},quad b=frac{36(x-y)}{x+y} $$
produce $b^2=a^3-432$, an elliptic curve. Similarly for the Fermat Curve of degree $4$, the substitutions
$$ a=frac{2(y^2+z^2)}{x^2},quad b=frac{4y(y^2+z^2)}{x^3} $$
give $b^2=a^3-4a$. However, the substitutions used are not at all obvious, which leads me to wonder,




Is there a similar substitution which can relate a Fermat curve of arbitrary degree to an elliptic curve?




How can we even begin to prove this? I suspect the proof or disproof of this statement will be way above my level; I truly have no clue where to begin. Can someone help out? If this is somehow an open problem, then any links to literature is also appreciated!





Edit: This question has been asked and answered on MO. (Yay!)










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
    $endgroup$
    – Eric Wofsey
    Dec 17 '18 at 1:31
















9












$begingroup$


A Fermat Curve of degree $n$ is the set of solutions to $x^n+y^n=z^n$, $x,y,zin mathbb R$. In this question, the OP provides a substitution which relates a Fermat Curve of degree $n=3,4$ to two different elliptic curves. To transform the Fermat Curve of degree $3$, the substitutions
$$ a=frac{12z}{x+y},quad b=frac{36(x-y)}{x+y} $$
produce $b^2=a^3-432$, an elliptic curve. Similarly for the Fermat Curve of degree $4$, the substitutions
$$ a=frac{2(y^2+z^2)}{x^2},quad b=frac{4y(y^2+z^2)}{x^3} $$
give $b^2=a^3-4a$. However, the substitutions used are not at all obvious, which leads me to wonder,




Is there a similar substitution which can relate a Fermat curve of arbitrary degree to an elliptic curve?




How can we even begin to prove this? I suspect the proof or disproof of this statement will be way above my level; I truly have no clue where to begin. Can someone help out? If this is somehow an open problem, then any links to literature is also appreciated!





Edit: This question has been asked and answered on MO. (Yay!)










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
    $endgroup$
    – Eric Wofsey
    Dec 17 '18 at 1:31














9












9








9


4



$begingroup$


A Fermat Curve of degree $n$ is the set of solutions to $x^n+y^n=z^n$, $x,y,zin mathbb R$. In this question, the OP provides a substitution which relates a Fermat Curve of degree $n=3,4$ to two different elliptic curves. To transform the Fermat Curve of degree $3$, the substitutions
$$ a=frac{12z}{x+y},quad b=frac{36(x-y)}{x+y} $$
produce $b^2=a^3-432$, an elliptic curve. Similarly for the Fermat Curve of degree $4$, the substitutions
$$ a=frac{2(y^2+z^2)}{x^2},quad b=frac{4y(y^2+z^2)}{x^3} $$
give $b^2=a^3-4a$. However, the substitutions used are not at all obvious, which leads me to wonder,




Is there a similar substitution which can relate a Fermat curve of arbitrary degree to an elliptic curve?




How can we even begin to prove this? I suspect the proof or disproof of this statement will be way above my level; I truly have no clue where to begin. Can someone help out? If this is somehow an open problem, then any links to literature is also appreciated!





Edit: This question has been asked and answered on MO. (Yay!)










share|cite|improve this question











$endgroup$




A Fermat Curve of degree $n$ is the set of solutions to $x^n+y^n=z^n$, $x,y,zin mathbb R$. In this question, the OP provides a substitution which relates a Fermat Curve of degree $n=3,4$ to two different elliptic curves. To transform the Fermat Curve of degree $3$, the substitutions
$$ a=frac{12z}{x+y},quad b=frac{36(x-y)}{x+y} $$
produce $b^2=a^3-432$, an elliptic curve. Similarly for the Fermat Curve of degree $4$, the substitutions
$$ a=frac{2(y^2+z^2)}{x^2},quad b=frac{4y(y^2+z^2)}{x^3} $$
give $b^2=a^3-4a$. However, the substitutions used are not at all obvious, which leads me to wonder,




Is there a similar substitution which can relate a Fermat curve of arbitrary degree to an elliptic curve?




How can we even begin to prove this? I suspect the proof or disproof of this statement will be way above my level; I truly have no clue where to begin. Can someone help out? If this is somehow an open problem, then any links to literature is also appreciated!





Edit: This question has been asked and answered on MO. (Yay!)







number-theory algebraic-geometry elliptic-curves algebraic-curves substitution






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 21 '18 at 9:50







YiFan

















asked Dec 17 '18 at 0:12









YiFanYiFan

3,7511527




3,7511527








  • 2




    $begingroup$
    In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
    $endgroup$
    – Eric Wofsey
    Dec 17 '18 at 1:31














  • 2




    $begingroup$
    In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
    $endgroup$
    – Eric Wofsey
    Dec 17 '18 at 1:31








2




2




$begingroup$
In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
$endgroup$
– Eric Wofsey
Dec 17 '18 at 1:31




$begingroup$
In the language of algebraic geometry, you're asking whether every Fermat curve has a nonconstant morphism to an elliptic curve.
$endgroup$
– Eric Wofsey
Dec 17 '18 at 1:31










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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3043380%2fis-there-a-substitution-which-transforms-every-fermat-curve-into-an-elliptic-cur%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%2f3043380%2fis-there-a-substitution-which-transforms-every-fermat-curve-into-an-elliptic-cur%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

Quarter-circle Tiles

build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

Mont Emei