Norm of the ring
$begingroup$
What is the norm of
$$mathbb{Z}[zeta] = [a_0 + a_1zeta + ...+a_{l-2}zeta^{l-2} : a_i in mathbb{Z}],$$
for $(l leq 19)$ prime, and $zeta$ root of unity, so $mathbb{Z}[zeta]$ is UFD.
It is easy when $l=3$, $(a+bzeta)(a+bbar{zeta}) = a^2 - ab+ b^2$
abstract-algebra
$endgroup$
add a comment |
$begingroup$
What is the norm of
$$mathbb{Z}[zeta] = [a_0 + a_1zeta + ...+a_{l-2}zeta^{l-2} : a_i in mathbb{Z}],$$
for $(l leq 19)$ prime, and $zeta$ root of unity, so $mathbb{Z}[zeta]$ is UFD.
It is easy when $l=3$, $(a+bzeta)(a+bbar{zeta}) = a^2 - ab+ b^2$
abstract-algebra
$endgroup$
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07
add a comment |
$begingroup$
What is the norm of
$$mathbb{Z}[zeta] = [a_0 + a_1zeta + ...+a_{l-2}zeta^{l-2} : a_i in mathbb{Z}],$$
for $(l leq 19)$ prime, and $zeta$ root of unity, so $mathbb{Z}[zeta]$ is UFD.
It is easy when $l=3$, $(a+bzeta)(a+bbar{zeta}) = a^2 - ab+ b^2$
abstract-algebra
$endgroup$
What is the norm of
$$mathbb{Z}[zeta] = [a_0 + a_1zeta + ...+a_{l-2}zeta^{l-2} : a_i in mathbb{Z}],$$
for $(l leq 19)$ prime, and $zeta$ root of unity, so $mathbb{Z}[zeta]$ is UFD.
It is easy when $l=3$, $(a+bzeta)(a+bbar{zeta}) = a^2 - ab+ b^2$
abstract-algebra
abstract-algebra
edited Dec 17 '18 at 10:43
Namaste
1
1
asked Aug 27 '18 at 11:59
Dogukan.NDogukan.N
112
112
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07
add a comment |
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07
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%2f2896115%2fnorm-of-the-ring%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%2f2896115%2fnorm-of-the-ring%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
$begingroup$
Not sure it is very easy : for a fixed element, would you not need to find the minimal polynomial or the conjugates of that element? For $l=3$ the conjugates were easy to find, but for larger $l$ this may be an issue.
$endgroup$
– астон вілла олоф мэллбэрг
Aug 27 '18 at 12:05
$begingroup$
Do you mean norm of an element, perhaps? (Note that UFDs may not be a Euclidean domain and so there may not be a Euclidean function)
$endgroup$
– daruma
Aug 27 '18 at 13:42
$begingroup$
@daruma, see Field norm
$endgroup$
– lhf
Dec 17 '18 at 11:06
$begingroup$
For $l=5$, see math.stackexchange.com/questions/24840/…. See also math.stackexchange.com/questions/175118/…
$endgroup$
– lhf
Dec 17 '18 at 11:07