Is $X + frac{2}{X}$ a rational quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
$begingroup$
First of all, I apologize for the rather silly question. This came up while I was scouring the Internet on a mathematical terminology appropriate for a concept that I need for a paper which I am currently writing.
So here it is:
Is $X + frac{2}{X}$ a rational quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
Or to put in another way:
Can the rational function $X + frac{2}{X}$ be represented by a quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
I know that I can just check Cassels' Rational Quadratic Forms, unfortunately the nearest university library is a bit far from my place of residence (not to mention being closed during the holidays).
quadratic-forms representations-by-quadratic-forms
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add a comment |
$begingroup$
First of all, I apologize for the rather silly question. This came up while I was scouring the Internet on a mathematical terminology appropriate for a concept that I need for a paper which I am currently writing.
So here it is:
Is $X + frac{2}{X}$ a rational quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
Or to put in another way:
Can the rational function $X + frac{2}{X}$ be represented by a quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
I know that I can just check Cassels' Rational Quadratic Forms, unfortunately the nearest university library is a bit far from my place of residence (not to mention being closed during the holidays).
quadratic-forms representations-by-quadratic-forms
$endgroup$
$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09
add a comment |
$begingroup$
First of all, I apologize for the rather silly question. This came up while I was scouring the Internet on a mathematical terminology appropriate for a concept that I need for a paper which I am currently writing.
So here it is:
Is $X + frac{2}{X}$ a rational quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
Or to put in another way:
Can the rational function $X + frac{2}{X}$ be represented by a quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
I know that I can just check Cassels' Rational Quadratic Forms, unfortunately the nearest university library is a bit far from my place of residence (not to mention being closed during the holidays).
quadratic-forms representations-by-quadratic-forms
$endgroup$
First of all, I apologize for the rather silly question. This came up while I was scouring the Internet on a mathematical terminology appropriate for a concept that I need for a paper which I am currently writing.
So here it is:
Is $X + frac{2}{X}$ a rational quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
Or to put in another way:
Can the rational function $X + frac{2}{X}$ be represented by a quadratic form, where $X in mathbb{Q} setminus mathbb{Z}$?
I know that I can just check Cassels' Rational Quadratic Forms, unfortunately the nearest university library is a bit far from my place of residence (not to mention being closed during the holidays).
quadratic-forms representations-by-quadratic-forms
quadratic-forms representations-by-quadratic-forms
edited Jan 25 at 8:10
Jose Arnaldo Bebita-Dris
asked Dec 31 '18 at 8:50
Jose Arnaldo Bebita-DrisJose Arnaldo Bebita-Dris
5,27452045
5,27452045
$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09
add a comment |
$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09
$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09
add a comment |
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$begingroup$
@flawr: I would go with the definition in Wikipedia, although honestly, I was not able to spot an actual definition for rational quadratic form but only for quadratic form per se.
$endgroup$
– Jose Arnaldo Bebita-Dris
Dec 31 '18 at 9:41
$begingroup$
My apologies! I meant to say $X in mathbb{Q} setminus mathbb{Z}$. Editing my question now to reflect this change.
$endgroup$
– Jose Arnaldo Bebita-Dris
Jan 25 at 8:09