Given a Multivariate Quotient Ring, can one find a Monoid ring with the same properties?












1












$begingroup$


Given a Polynomial ring, say $$S = R[x,y]/(x^2+x-1,y^3-y)$$ Is there a Monoid M and a ring $$T = R[M] cong S?$$ If there is such a Monoid what would it be? I am able to find one for univariate S:
$R$ is any ring with unity. $$S = R[x]/(p(x)),qquad n = deg(p)$$ assuming $p(x)$ is monic over $R$. The basis is of $T$ is $B[k]$ with $k in Bbb{Z}/nBbb{Z}$,
$R[Bbb{Z}/nBbb{Z}]$ with the basis action $f(a,b)$ being:
$$sum_{k=0}^{n-1} -c_{k}*B[k+a+b mod n] | a+b < min(a,b)
quad text{or}quad a+bquad text{otherwise}$$










share|cite|improve this question











$endgroup$












  • $begingroup$
    The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:07










  • $begingroup$
    I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
    $endgroup$
    – Malachi Wadas
    Dec 28 '18 at 7:13










  • $begingroup$
    In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:18












  • $begingroup$
    I assume that your definition of a monoid ring parallels that of the group ring.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:21






  • 1




    $begingroup$
    From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
    $endgroup$
    – Malachi Wadas
    Dec 29 '18 at 3:32


















1












$begingroup$


Given a Polynomial ring, say $$S = R[x,y]/(x^2+x-1,y^3-y)$$ Is there a Monoid M and a ring $$T = R[M] cong S?$$ If there is such a Monoid what would it be? I am able to find one for univariate S:
$R$ is any ring with unity. $$S = R[x]/(p(x)),qquad n = deg(p)$$ assuming $p(x)$ is monic over $R$. The basis is of $T$ is $B[k]$ with $k in Bbb{Z}/nBbb{Z}$,
$R[Bbb{Z}/nBbb{Z}]$ with the basis action $f(a,b)$ being:
$$sum_{k=0}^{n-1} -c_{k}*B[k+a+b mod n] | a+b < min(a,b)
quad text{or}quad a+bquad text{otherwise}$$










share|cite|improve this question











$endgroup$












  • $begingroup$
    The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:07










  • $begingroup$
    I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
    $endgroup$
    – Malachi Wadas
    Dec 28 '18 at 7:13










  • $begingroup$
    In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:18












  • $begingroup$
    I assume that your definition of a monoid ring parallels that of the group ring.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:21






  • 1




    $begingroup$
    From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
    $endgroup$
    – Malachi Wadas
    Dec 29 '18 at 3:32
















1












1








1





$begingroup$


Given a Polynomial ring, say $$S = R[x,y]/(x^2+x-1,y^3-y)$$ Is there a Monoid M and a ring $$T = R[M] cong S?$$ If there is such a Monoid what would it be? I am able to find one for univariate S:
$R$ is any ring with unity. $$S = R[x]/(p(x)),qquad n = deg(p)$$ assuming $p(x)$ is monic over $R$. The basis is of $T$ is $B[k]$ with $k in Bbb{Z}/nBbb{Z}$,
$R[Bbb{Z}/nBbb{Z}]$ with the basis action $f(a,b)$ being:
$$sum_{k=0}^{n-1} -c_{k}*B[k+a+b mod n] | a+b < min(a,b)
quad text{or}quad a+bquad text{otherwise}$$










share|cite|improve this question











$endgroup$




Given a Polynomial ring, say $$S = R[x,y]/(x^2+x-1,y^3-y)$$ Is there a Monoid M and a ring $$T = R[M] cong S?$$ If there is such a Monoid what would it be? I am able to find one for univariate S:
$R$ is any ring with unity. $$S = R[x]/(p(x)),qquad n = deg(p)$$ assuming $p(x)$ is monic over $R$. The basis is of $T$ is $B[k]$ with $k in Bbb{Z}/nBbb{Z}$,
$R[Bbb{Z}/nBbb{Z}]$ with the basis action $f(a,b)$ being:
$$sum_{k=0}^{n-1} -c_{k}*B[k+a+b mod n] | a+b < min(a,b)
quad text{or}quad a+bquad text{otherwise}$$







abstract-algebra






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 28 '18 at 7:37







Malachi Wadas

















asked Dec 28 '18 at 4:55









Malachi WadasMalachi Wadas

112




112












  • $begingroup$
    The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:07










  • $begingroup$
    I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
    $endgroup$
    – Malachi Wadas
    Dec 28 '18 at 7:13










  • $begingroup$
    In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:18












  • $begingroup$
    I assume that your definition of a monoid ring parallels that of the group ring.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:21






  • 1




    $begingroup$
    From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
    $endgroup$
    – Malachi Wadas
    Dec 29 '18 at 3:32




















  • $begingroup$
    The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:07










  • $begingroup$
    I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
    $endgroup$
    – Malachi Wadas
    Dec 28 '18 at 7:13










  • $begingroup$
    In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:18












  • $begingroup$
    I assume that your definition of a monoid ring parallels that of the group ring.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 7:21






  • 1




    $begingroup$
    From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
    $endgroup$
    – Malachi Wadas
    Dec 29 '18 at 3:32


















$begingroup$
The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:07




$begingroup$
The product of basis elements must agree with the operation of the monoid, so I don't think $R[x]/langle p(x)rangle$ works for all polynomials of degree $n$. It does work for $M=Bbb{Z}/nBbb{Z}$ when $p(x)=x^n-1$ (other polynomials may also work depending on the ring $R$),
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:07












$begingroup$
I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
$endgroup$
– Malachi Wadas
Dec 28 '18 at 7:13




$begingroup$
I’ve used sage math to test it my self and it works for any polynomial, the operation is associative as well, with 0 as the unit, I am currently working with R being The Reals or Complexes
$endgroup$
– Malachi Wadas
Dec 28 '18 at 7:13












$begingroup$
In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:18






$begingroup$
In the ring $R[M]$ with basis $B[m], min M$ the product must be $B[m_1]*B[m_2]=B[m_1cdot m_2]$. I don't think you have that. Here $m_1cdot m_2$ is the operation of your monoid $M$.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:18














$begingroup$
I assume that your definition of a monoid ring parallels that of the group ring.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:21




$begingroup$
I assume that your definition of a monoid ring parallels that of the group ring.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 7:21




1




1




$begingroup$
From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
$endgroup$
– Malachi Wadas
Dec 29 '18 at 3:32






$begingroup$
From what you given it seems any polynomials of the form $$x^{p} - x^{q} = 0; p > q $$ Form a Monoid ring.
$endgroup$
– Malachi Wadas
Dec 29 '18 at 3:32












1 Answer
1






active

oldest

votes


















0












$begingroup$

Multiplicatively, its the monoid (ring extension of $R$) $R[bar x,bar y]$, where $bar x^3 + bar x - 1 = bar 0$ and $bar y^3 - bar y = bar 0$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 9:07













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%2f3054578%2fgiven-a-multivariate-quotient-ring-can-one-find-a-monoid-ring-with-the-same-pro%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









0












$begingroup$

Multiplicatively, its the monoid (ring extension of $R$) $R[bar x,bar y]$, where $bar x^3 + bar x - 1 = bar 0$ and $bar y^3 - bar y = bar 0$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 9:07


















0












$begingroup$

Multiplicatively, its the monoid (ring extension of $R$) $R[bar x,bar y]$, where $bar x^3 + bar x - 1 = bar 0$ and $bar y^3 - bar y = bar 0$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 9:07
















0












0








0





$begingroup$

Multiplicatively, its the monoid (ring extension of $R$) $R[bar x,bar y]$, where $bar x^3 + bar x - 1 = bar 0$ and $bar y^3 - bar y = bar 0$.






share|cite|improve this answer











$endgroup$



Multiplicatively, its the monoid (ring extension of $R$) $R[bar x,bar y]$, where $bar x^3 + bar x - 1 = bar 0$ and $bar y^3 - bar y = bar 0$.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 28 '18 at 8:25

























answered Dec 28 '18 at 7:50









WuestenfuxWuestenfux

4,7291513




4,7291513












  • $begingroup$
    This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 9:07




















  • $begingroup$
    This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
    $endgroup$
    – Jyrki Lahtonen
    Dec 28 '18 at 9:07


















$begingroup$
This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 9:07






$begingroup$
This is not what a monoid ring is. If $M$ is a (multiplicative) monoid, the monoid ring $R[M]$ is the ring of formal linear combinations $sum_{min M} r_m m$ with $r_min R$ for all $min M$, componentwise addition, and multiplication extending $R$-linearly the multiplication in $M$.
$endgroup$
– Jyrki Lahtonen
Dec 28 '18 at 9:07




















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%2f3054578%2fgiven-a-multivariate-quotient-ring-can-one-find-a-monoid-ring-with-the-same-pro%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