Invariants
Base field: | $\F_{5}$ |
Dimension: | $2$ |
L-polynomial: | $1 - 2 x + 6 x^{2} - 10 x^{3} + 25 x^{4}$ |
Frobenius angles: | $\pm0.242482928382$, $\pm0.589139206307$ |
Angle rank: | $2$ (numerical) |
Number field: | 4.0.4400.1 |
Galois group: | $D_{4}$ |
Jacobians: | $6$ |
Isomorphism classes: | 8 |
This isogeny class is simple and geometrically simple, primitive, ordinary, and not supersingular. It is principally polarizable and contains a Jacobian.
Newton polygon
This isogeny class is ordinary.
$p$-rank: | $2$ |
Slopes: | $[0, 0, 1, 1]$ |
Point counts
Point counts of the abelian variety
$r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
---|---|---|---|---|---|
$A(\F_{q^r})$ | $20$ | $880$ | $15380$ | $408320$ | $10400500$ |
$r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
---|---|---|---|---|---|---|---|---|---|---|
$C(\F_{q^r})$ | $4$ | $34$ | $124$ | $654$ | $3324$ | $15634$ | $77284$ | $390174$ | $1952404$ | $9758274$ |
Jacobians and polarizations
This isogeny class contains the Jacobians of 6 curves (of which all are hyperelliptic), and hence is principally polarizable:
- $y^2=2x^6+3x^5+x^4+4x+3$
- $y^2=3x^5+4x^4+2$
- $y^2=3x^5+x^4+x+3$
- $y^2=2x^6+4x^4+3x^3+4x^2+4x$
- $y^2=3x^6+x^5+4x^4+4x^2+x+2$
- $y^2=4x^6+3x^5+x^4+x^3+2x+3$
Decomposition and endomorphism algebra
All geometric endomorphisms are defined over $\F_{5}$.
Endomorphism algebra over $\F_{5}$The endomorphism algebra of this simple isogeny class is 4.0.4400.1. |
Base change
This is a primitive isogeny class.
Twists
Below is a list of all twists of this isogeny class.
Twist | Extension degree | Common base change |
---|---|---|
2.5.c_g | $2$ | 2.25.i_bu |