Invariants
| Base field: | $\F_{31}$ |
| Dimension: | $2$ |
| L-polynomial: | $1 - 4 x + 6 x^{2} - 124 x^{3} + 961 x^{4}$ |
| Frobenius angles: | $\pm0.160720718826$, $\pm0.672580684872$ |
| Angle rank: | $2$ (numerical) |
| Number field: | 4.0.2376000.2 |
| Galois group: | $D_{4}$ |
| Jacobians: | $112$ |
| Cyclic group of points: | no |
| Non-cyclic primes: | $2$ |
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
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $A(\F_{q^r})$ | $840$ | $920640$ | $876725640$ | $854663255040$ | $820006173525000$ |
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
|---|---|---|---|---|---|---|---|---|---|---|
| $C(\F_{q^r})$ | $28$ | $958$ | $29428$ | $925438$ | $28642348$ | $887503678$ | $27513122308$ | $852892865278$ | $26439613740988$ | $819628305355198$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 112 curves (of which all are hyperelliptic):
- $y^2=10 x^6+23 x^5+6 x^4+13 x^2+2 x+5$
- $y^2=29 x^6+19 x^5+7 x^4+20 x^3+6 x^2+27 x+11$
- $y^2=21 x^6+7 x^5+25 x^4+8 x^3+19 x^2+8 x+6$
- $y^2=22 x^6+6 x^5+29 x^4+13 x^3+12 x^2+6 x+1$
- $y^2=12 x^6+13 x^5+9 x^4+29 x^3+30 x^2+30 x+22$
- $y^2=x^6+23 x^5+21 x^4+20 x^3+9 x^2+7 x+11$
- $y^2=16 x^6+26 x^5+26 x^4+8 x^3+4 x^2+14 x+21$
- $y^2=x^6+18 x^5+6 x^4+7 x^3+23 x^2+12 x+23$
- $y^2=14 x^6+17 x^5+17 x^4+4 x^3+16 x^2+21 x+15$
- $y^2=9 x^6+21 x^4+13 x^3+28 x^2+19 x+12$
- $y^2=3 x^6+21 x^5+18 x^4+18 x^3+28 x^2+10 x$
- $y^2=4 x^6+7 x^5+17 x^4+16 x^3+23 x^2+12 x+4$
- $y^2=8 x^6+27 x^5+8 x^4+23 x^3+27 x^2+19 x+14$
- $y^2=22 x^6+22 x^5+2 x^4+15 x^3+20 x^2+17 x+5$
- $y^2=22 x^6+14 x^5+12 x^4+10 x^3+19 x^2+9 x+17$
- $y^2=15 x^6+13 x^5+30 x^4+2 x^3+13 x^2+5 x+20$
- $y^2=24 x^6+x^4+30 x^3+27 x^2+16 x+7$
- $y^2=16 x^5+13 x^4+20 x^3+3 x^2+8 x+22$
- $y^2=13 x^6+28 x^5+29 x^4+14 x^3+15 x^2+13 x+22$
- $y^2=5 x^6+9 x^5+3 x^3+2 x^2+12 x+7$
- and 92 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 4.0.2376000.2. |
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.e_g | $2$ | (not in LMFDB) |