Invariants
| Base field: | $\F_{31}$ |
| Dimension: | $2$ |
| L-polynomial: | $1 + 4 x + 54 x^{2} + 124 x^{3} + 961 x^{4}$ |
| Frobenius angles: | $\pm0.458027021365$, $\pm0.663255536989$ |
| Angle rank: | $2$ (numerical) |
| Number field: | 4.0.412992.5 |
| Galois group: | $D_{4}$ |
| Jacobians: | $56$ |
| 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
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $A(\F_{q^r})$ | $1144$ | $1015872$ | $881201464$ | $852178449408$ | $819607807488184$ |
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
|---|---|---|---|---|---|---|---|---|---|---|
| $C(\F_{q^r})$ | $36$ | $1054$ | $29580$ | $922750$ | $28628436$ | $887486110$ | $27513022524$ | $852891183358$ | $26439602389764$ | $819628324428574$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 56 curves (of which all are hyperelliptic):
- $y^2=19 x^6+28 x^5+20 x^4+9 x^2+25 x+24$
- $y^2=3 x^6+15 x^5+6 x^4+6 x^3+8 x^2+24 x+28$
- $y^2=11 x^6+27 x^5+5 x^4+3 x^3+10 x^2+13 x+6$
- $y^2=8 x^6+10 x^5+23 x^4+22 x^3+29 x^2+10 x+27$
- $y^2=9 x^6+7 x^5+11 x^4+19 x^3+15 x^2+x$
- $y^2=9 x^6+x^5+5 x^4+22 x^3+26 x^2+17 x+28$
- $y^2=16 x^6+24 x^5+5 x^4+5 x^3+23 x^2+x+22$
- $y^2=17 x^6+16 x^5+11 x^3+28 x^2+9 x+7$
- $y^2=5 x^6+2 x^4+22 x^3+27 x^2+21 x+17$
- $y^2=12 x^6+18 x^5+2 x^4+11 x^3+10 x^2+27 x+19$
- $y^2=14 x^6+19 x^5+22 x^4+14 x^3+29 x^2+16 x+6$
- $y^2=2 x^6+25 x^5+13 x^4+24 x^2+22$
- $y^2=x^6+15 x^5+19 x^4+24 x^3+17 x^2+14$
- $y^2=20 x^6+28 x^5+20 x^4+19 x^3+4 x^2+6 x+30$
- $y^2=4 x^6+8 x^5+13 x^4+8 x^3+x^2+22 x+10$
- $y^2=19 x^6+15 x^5+4 x^4+22 x^3+23 x^2+8 x+17$
- $y^2=15 x^6+15 x^5+21 x^4+18 x^3+12 x^2+16 x+25$
- $y^2=7 x^6+9 x^5+17 x^4+24 x^3+21 x^2+29 x+16$
- $y^2=8 x^6+10 x^5+27 x^4+8 x^3+11 x^2+23 x+18$
- $y^2=4 x^6+11 x^5+25 x^4+30 x^3+6 x^2+25 x+27$
- 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 4.0.412992.5. |
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.ae_cc | $2$ | (not in LMFDB) |