Sums of two integer squares in arithmetic progressions
$begingroup$
Is there an explicit formula in the literature for the number of representations of a positive integer $n$ as a sum of two integer squares, the second of which is divisible by $5$? So this means to count integer representations of $n$ by the quadratic form $x^2+ 5^2 y^2$.
I would hope for something as nice as the formula related to representations as a sum of two integer squares,
$$ sum_{substack{ din mathbb{N} \ d text{ divides } n}} chi(d),$$ where $chi$ is the non-principal character modulo $4$.
In general, I would be interested in the number of representations by any quadratic form of the shape $d_1^2 x^2+ d_2^2 y^2$, where $d_1,d_2$ are non-zero integers.
nt.number-theory algebraic-number-theory quadratic-forms
$endgroup$
add a comment |
$begingroup$
Is there an explicit formula in the literature for the number of representations of a positive integer $n$ as a sum of two integer squares, the second of which is divisible by $5$? So this means to count integer representations of $n$ by the quadratic form $x^2+ 5^2 y^2$.
I would hope for something as nice as the formula related to representations as a sum of two integer squares,
$$ sum_{substack{ din mathbb{N} \ d text{ divides } n}} chi(d),$$ where $chi$ is the non-principal character modulo $4$.
In general, I would be interested in the number of representations by any quadratic form of the shape $d_1^2 x^2+ d_2^2 y^2$, where $d_1,d_2$ are non-zero integers.
nt.number-theory algebraic-number-theory quadratic-forms
$endgroup$
4
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50
add a comment |
$begingroup$
Is there an explicit formula in the literature for the number of representations of a positive integer $n$ as a sum of two integer squares, the second of which is divisible by $5$? So this means to count integer representations of $n$ by the quadratic form $x^2+ 5^2 y^2$.
I would hope for something as nice as the formula related to representations as a sum of two integer squares,
$$ sum_{substack{ din mathbb{N} \ d text{ divides } n}} chi(d),$$ where $chi$ is the non-principal character modulo $4$.
In general, I would be interested in the number of representations by any quadratic form of the shape $d_1^2 x^2+ d_2^2 y^2$, where $d_1,d_2$ are non-zero integers.
nt.number-theory algebraic-number-theory quadratic-forms
$endgroup$
Is there an explicit formula in the literature for the number of representations of a positive integer $n$ as a sum of two integer squares, the second of which is divisible by $5$? So this means to count integer representations of $n$ by the quadratic form $x^2+ 5^2 y^2$.
I would hope for something as nice as the formula related to representations as a sum of two integer squares,
$$ sum_{substack{ din mathbb{N} \ d text{ divides } n}} chi(d),$$ where $chi$ is the non-principal character modulo $4$.
In general, I would be interested in the number of representations by any quadratic form of the shape $d_1^2 x^2+ d_2^2 y^2$, where $d_1,d_2$ are non-zero integers.
nt.number-theory algebraic-number-theory quadratic-forms
nt.number-theory algebraic-number-theory quadratic-forms
asked Feb 1 at 15:59
Captain DarlingCaptain Darling
1,251818
1,251818
4
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50
add a comment |
4
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50
4
4
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50
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: "504"
};
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%2fmathoverflow.net%2fquestions%2f322231%2fsums-of-two-integer-squares-in-arithmetic-progressions%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 MathOverflow!
- 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%2fmathoverflow.net%2fquestions%2f322231%2fsums-of-two-integer-squares-in-arithmetic-progressions%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
4
$begingroup$
Things are not so simple in general. Have a look at the book amazon.com/Primes-Form-x2-ny2-Multiplication/dp/1118390180
$endgroup$
– GH from MO
Feb 1 at 20:14
$begingroup$
yes that is a great but how is it useful? the square coefficients make all the quadratic forms in the question equivalent to $x^2+y^2$ so not sure how quadratic fields etc.etc. are relevant.
$endgroup$
– Captain Darling
Feb 7 at 8:33
$begingroup$
I believe that the kind of formula you expect does not exist. Unfortuately, I am no expert here, and I don't have the time to check the literature.
$endgroup$
– GH from MO
Feb 7 at 18:50