Attributes of Genus One Models

Degree(model) : ModelG1 -> RngIntElt
The degree (2, 3, 4, or 5) of the given model.
DefiningEquations(model) : ModelG1 -> [ RngMPolElt ]
A sequence containing the equations by which the given genus one model (which must have degree 2, 3, or 4) is defined.
Equations(model) : ModelG1 -> [ RngMPolElt ]
A sequence containing equations for the scheme associated to the given genus one model (of any degree). For degree 2, 3, or 4 this is the same as DefiningEquations.
Matrix(model) : ModelG1 -> Mtrx
The defining matrix of a genus one model of degree 5.
Curve(model) : ModelG1 -> Crv
HyperellipticCurve(model) : ModelG1 -> CrvHyp
QuadricIntersection(model) : ModelG1 -> Crv
The curve associated to the given genus one model.

In the degree 2 case the curve is hyperelliptic of the form y2 + f(x, z) y - g(x, z) = 0, but is only created explicitly as a hyperelliptic curve when HyperellipticCurve is called; otherwise it is created as a general curve in a weighted projective space in which the variables x, z, and y have weights 1, 1, and 2).

In the degree 4 case the curve is an intersection of two quadrics in P3.

An error results in degenerate cases where the equations of the model do not define a curve

Matrices(model) : ModelG1 -> [ AlgMatElt ]
For a genus one model of degree 4 this function returns a sequence containing two 4 x 4 symmetric matrices representing the quadrics.
BaseRing(model) : ModelG1 -> Rng
The coefficient ring of the given model.
PolynomialRing(model) : ModelG1 -> RngMPol
The polynomial ring used to define the model.
ModelToSequence(model) : ModelG1 -> [ RngElt ]
Eltseq(model) : ModelG1 -> [ RngElt ]
A sequence containing the defining coefficients of the given genus one model.
ModelToString(model) : ModelG1 -> MonStgElt
A string containing the defining coefficients of the given genus one model.
V2.28, 13 July 2023