Non-singular elliptic curve parametrization
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It is known that some singular elliptic curves can be expressed with parametric equations.
For example :
$y^2=x^3$ can be parametrized with $x=t^2$ and $y=t^3$
$y^2=x^3+x^2$ can be parametrized with $x=t^2-1$ and $y=t^3-t$ [source]
But, is there any parametric equations for some non-singular elliptic curves with a graph looking like :
simple elliptic curve
And if yes, what would be the correct way to obtain it.
We could assume that it can be represented by : $y^2 = f(x)$
where $f(x)=x^3+ax^2+bx+c$ have only one simple real root.
algebraic-geometry elliptic-curves parametrization elliptic-equations
$endgroup$
|
show 2 more comments
$begingroup$
It is known that some singular elliptic curves can be expressed with parametric equations.
For example :
$y^2=x^3$ can be parametrized with $x=t^2$ and $y=t^3$
$y^2=x^3+x^2$ can be parametrized with $x=t^2-1$ and $y=t^3-t$ [source]
But, is there any parametric equations for some non-singular elliptic curves with a graph looking like :
simple elliptic curve
And if yes, what would be the correct way to obtain it.
We could assume that it can be represented by : $y^2 = f(x)$
where $f(x)=x^3+ax^2+bx+c$ have only one simple real root.
algebraic-geometry elliptic-curves parametrization elliptic-equations
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2
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There are no rational parametrization. You need the elliptic functions or similar.
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– user10354138
Jan 5 at 11:31
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Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
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– Yoshi
Jan 5 at 11:37
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@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
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Sorry but, what's the question?
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– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47
|
show 2 more comments
$begingroup$
It is known that some singular elliptic curves can be expressed with parametric equations.
For example :
$y^2=x^3$ can be parametrized with $x=t^2$ and $y=t^3$
$y^2=x^3+x^2$ can be parametrized with $x=t^2-1$ and $y=t^3-t$ [source]
But, is there any parametric equations for some non-singular elliptic curves with a graph looking like :
simple elliptic curve
And if yes, what would be the correct way to obtain it.
We could assume that it can be represented by : $y^2 = f(x)$
where $f(x)=x^3+ax^2+bx+c$ have only one simple real root.
algebraic-geometry elliptic-curves parametrization elliptic-equations
$endgroup$
It is known that some singular elliptic curves can be expressed with parametric equations.
For example :
$y^2=x^3$ can be parametrized with $x=t^2$ and $y=t^3$
$y^2=x^3+x^2$ can be parametrized with $x=t^2-1$ and $y=t^3-t$ [source]
But, is there any parametric equations for some non-singular elliptic curves with a graph looking like :
simple elliptic curve
And if yes, what would be the correct way to obtain it.
We could assume that it can be represented by : $y^2 = f(x)$
where $f(x)=x^3+ax^2+bx+c$ have only one simple real root.
algebraic-geometry elliptic-curves parametrization elliptic-equations
algebraic-geometry elliptic-curves parametrization elliptic-equations
edited Jan 5 at 18:33
Yoshi
asked Jan 5 at 11:19
YoshiYoshi
133
133
2
$begingroup$
There are no rational parametrization. You need the elliptic functions or similar.
$endgroup$
– user10354138
Jan 5 at 11:31
$begingroup$
Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
$endgroup$
– Yoshi
Jan 5 at 11:37
$begingroup$
@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
$begingroup$
Sorry but, what's the question?
$endgroup$
– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47
|
show 2 more comments
2
$begingroup$
There are no rational parametrization. You need the elliptic functions or similar.
$endgroup$
– user10354138
Jan 5 at 11:31
$begingroup$
Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
$endgroup$
– Yoshi
Jan 5 at 11:37
$begingroup$
@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
$begingroup$
Sorry but, what's the question?
$endgroup$
– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47
2
2
$begingroup$
There are no rational parametrization. You need the elliptic functions or similar.
$endgroup$
– user10354138
Jan 5 at 11:31
$begingroup$
There are no rational parametrization. You need the elliptic functions or similar.
$endgroup$
– user10354138
Jan 5 at 11:31
$begingroup$
Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
$endgroup$
– Yoshi
Jan 5 at 11:37
$begingroup$
Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
$endgroup$
– Yoshi
Jan 5 at 11:37
$begingroup$
@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
$begingroup$
@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
$begingroup$
Sorry but, what's the question?
$endgroup$
– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
Sorry but, what's the question?
$endgroup$
– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47
|
show 2 more comments
1 Answer
1
active
oldest
votes
$begingroup$
First, there are not "singular elliptic curves", you want to say "singular curves given by a Weierstrass equation".
Now, if you want to do such parametrization (through polynomials) to a curve given by a Weierstrass equation, if the curve is non-singular, that can not be done. If your curve $C$ is defined over $mathbb{P}^2$ over $mathbb{C}$, you will have a regular (holomorphic) map
begin{align}
phi:mathbb{P}^1to C.
end{align}
By the Riemann-Hurwitz Theorem, as $phi$ is surjective, the genus of the codomain must be less or equal to the genus of the domain. But, the genus of $C$ is $1$, and the genus of $mathbb{P}^1$ is zero.
$endgroup$
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$begingroup$
First, there are not "singular elliptic curves", you want to say "singular curves given by a Weierstrass equation".
Now, if you want to do such parametrization (through polynomials) to a curve given by a Weierstrass equation, if the curve is non-singular, that can not be done. If your curve $C$ is defined over $mathbb{P}^2$ over $mathbb{C}$, you will have a regular (holomorphic) map
begin{align}
phi:mathbb{P}^1to C.
end{align}
By the Riemann-Hurwitz Theorem, as $phi$ is surjective, the genus of the codomain must be less or equal to the genus of the domain. But, the genus of $C$ is $1$, and the genus of $mathbb{P}^1$ is zero.
$endgroup$
add a comment |
$begingroup$
First, there are not "singular elliptic curves", you want to say "singular curves given by a Weierstrass equation".
Now, if you want to do such parametrization (through polynomials) to a curve given by a Weierstrass equation, if the curve is non-singular, that can not be done. If your curve $C$ is defined over $mathbb{P}^2$ over $mathbb{C}$, you will have a regular (holomorphic) map
begin{align}
phi:mathbb{P}^1to C.
end{align}
By the Riemann-Hurwitz Theorem, as $phi$ is surjective, the genus of the codomain must be less or equal to the genus of the domain. But, the genus of $C$ is $1$, and the genus of $mathbb{P}^1$ is zero.
$endgroup$
add a comment |
$begingroup$
First, there are not "singular elliptic curves", you want to say "singular curves given by a Weierstrass equation".
Now, if you want to do such parametrization (through polynomials) to a curve given by a Weierstrass equation, if the curve is non-singular, that can not be done. If your curve $C$ is defined over $mathbb{P}^2$ over $mathbb{C}$, you will have a regular (holomorphic) map
begin{align}
phi:mathbb{P}^1to C.
end{align}
By the Riemann-Hurwitz Theorem, as $phi$ is surjective, the genus of the codomain must be less or equal to the genus of the domain. But, the genus of $C$ is $1$, and the genus of $mathbb{P}^1$ is zero.
$endgroup$
First, there are not "singular elliptic curves", you want to say "singular curves given by a Weierstrass equation".
Now, if you want to do such parametrization (through polynomials) to a curve given by a Weierstrass equation, if the curve is non-singular, that can not be done. If your curve $C$ is defined over $mathbb{P}^2$ over $mathbb{C}$, you will have a regular (holomorphic) map
begin{align}
phi:mathbb{P}^1to C.
end{align}
By the Riemann-Hurwitz Theorem, as $phi$ is surjective, the genus of the codomain must be less or equal to the genus of the domain. But, the genus of $C$ is $1$, and the genus of $mathbb{P}^1$ is zero.
answered Jan 5 at 12:05
José Alejandro Aburto AranedaJosé Alejandro Aburto Araneda
802110
802110
add a comment |
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$begingroup$
There are no rational parametrization. You need the elliptic functions or similar.
$endgroup$
– user10354138
Jan 5 at 11:31
$begingroup$
Thank you ! However I didn't said it but i'm not necessarily looking for a rational parametrization
$endgroup$
– Yoshi
Jan 5 at 11:37
$begingroup$
@Yoshi "rational" means the parameters live in $mathbb C cup { infty }$.
$endgroup$
– Kenny Wong
Jan 5 at 11:44
$begingroup$
Sorry but, what's the question?
$endgroup$
– José Alejandro Aburto Araneda
Jan 5 at 11:45
$begingroup$
@KennyWong Oh ok, translation mistake ! Thank you !
$endgroup$
– Yoshi
Jan 5 at 11:47