Invariants
Base field: | $\F_{31}$ |
Dimension: | $2$ |
L-polynomial: | $1 - 5 x + 54 x^{2} - 155 x^{3} + 961 x^{4}$ |
Frobenius angles: | $\pm0.309452862742$, $\pm0.536523691511$ |
Angle rank: | $2$ (numerical) |
Number field: | 4.0.8411661.1 |
Galois group: | $D_{4}$ |
Jacobians: | $56$ |
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
$r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
---|---|---|---|---|---|
$A(\F_{q^r})$ | $856$ | $1006656$ | $894078304$ | $852601392384$ | $819749293211176$ |
$r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
---|---|---|---|---|---|---|---|---|---|---|
$C(\F_{q^r})$ | $27$ | $1045$ | $30012$ | $923209$ | $28633377$ | $887496046$ | $27512087847$ | $852889774129$ | $26439639018612$ | $819628365256525$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 56 curves (of which all are hyperelliptic):
- $y^2=10 x^6+28 x^5+4 x^4+24 x^3+7 x^2+30 x+26$
- $y^2=21 x^5+19 x^4+22 x^3+17 x^2+21 x+29$
- $y^2=28 x^6+14 x^4+10 x^3+8 x^2+2$
- $y^2=30 x^6+13 x^5+19 x^4+8 x^3+6 x^2+3 x+29$
- $y^2=15 x^6+6 x^5+25 x^4+6 x^3+20 x^2+17 x+11$
- $y^2=6 x^6+21 x^4+14 x^3+3 x^2+20 x+11$
- $y^2=6 x^6+12 x^5+20 x^4+25 x^3+x^2+3 x+21$
- $y^2=x^6+24 x^5+26 x^4+x^3+18 x^2+24 x+12$
- $y^2=x^6+20 x^5+21 x^4+27 x^3+18 x^2+18 x$
- $y^2=12 x^6+29 x^5+4 x^4+4 x^3+26 x^2+14 x+3$
- $y^2=9 x^6+29 x^5+26 x^4+6 x^3+29 x^2+6 x+23$
- $y^2=23 x^6+24 x^5+28 x^4+28 x^3+24 x^2+27 x+27$
- $y^2=7 x^6+20 x^5+5 x^4+14 x^3+23 x^2+28 x+30$
- $y^2=24 x^6+25 x^5+5 x^4+12 x^3+21 x^2+10 x+10$
- $y^2=15 x^6+30 x^5+10 x^4+4 x^3+x^2+5 x+30$
- $y^2=5 x^6+11 x^5+11 x^4+6 x^3+17 x^2+22 x+29$
- $y^2=21 x^6+14 x^5+11 x^4+20 x^3+6 x^2+9 x+8$
- $y^2=6 x^6+22 x^5+7 x^4+30 x^3+3 x^2+10 x+13$
- $y^2=27 x^6+4 x^5+18 x^3+9 x^2+23 x$
- $y^2=30 x^6+23 x^5+19 x^4+x^3+14 x^2+6 x+29$
- and 36 more
Decomposition and endomorphism algebra
All geometric endomorphisms are defined over $\F_{31}$.
Endomorphism algebra over $\F_{31}$The endomorphism algebra of this simple isogeny class is 4.0.8411661.1. |
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 |
---|---|---|
2.31.f_cc | $2$ | (not in LMFDB) |