Invariants
| Base field: | $\F_{7}$ |
| Dimension: | $2$ |
| L-polynomial: | $1 - 6 x + 18 x^{2} - 42 x^{3} + 49 x^{4}$ |
| Frobenius angles: | $\pm0.0461154155528$, $\pm0.453884584447$ |
| Angle rank: | $1$ (numerical) |
| Number field: | \(\Q(i, \sqrt{5})\) |
| Galois group: | $C_2^2$ |
| Jacobians: | $2$ |
| Isomorphism classes: | 3 |
This isogeny class is simple but not 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
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $A(\F_{q^r})$ | $20$ | $2320$ | $111620$ | $5382400$ | $276390500$ |
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
|---|---|---|---|---|---|---|---|---|---|---|
| $C(\F_{q^r})$ | $2$ | $50$ | $326$ | $2238$ | $16442$ | $117650$ | $824126$ | $5760958$ | $40338002$ | $282475250$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 2 curves (of which all are hyperelliptic):
- $y^2=6x^6+4x^5+6x^4+6x^2+3x+6$
- $y^2=4x^6+3x^4+4x^3+5x^2+4x+6$
Decomposition and endomorphism algebra
All geometric endomorphisms are defined over $\F_{7^{4}}$.
Endomorphism algebra over $\F_{7}$| The endomorphism algebra of this simple isogeny class is \(\Q(i, \sqrt{5})\). |
| The base change of $A$ to $\F_{7^{4}}$ is 1.2401.ade 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-5}) \)$)$ |
- Endomorphism algebra over $\F_{7^{2}}$
The base change of $A$ to $\F_{7^{2}}$ is the simple isogeny class 2.49.a_ade and its endomorphism algebra is \(\Q(i, \sqrt{5})\).
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 |
|---|---|---|
| 2.7.g_s | $2$ | 2.49.a_ade |
| 2.7.a_ae | $8$ | (not in LMFDB) |
| 2.7.a_e | $8$ | (not in LMFDB) |