Properties

Label 2.7.a_a
Base field $\F_{7}$
Dimension $2$
$p$-rank $0$
Ordinary no
Supersingular yes
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{7}$
Dimension:  $2$
L-polynomial:  $1 + 49 x^{4}$
Frobenius angles:  $\pm0.250000000000$, $\pm0.750000000000$
Angle rank:  $0$ (numerical)
Number field:  \(\Q(i, \sqrt{14})\)
Galois group:  $C_2^2$
Jacobians:  $9$

This isogeny class is simple but not geometrically simple, primitive, not ordinary, and supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

This isogeny class is supersingular.

$p$-rank:  $0$
Slopes:  $[1/2, 1/2, 1/2, 1/2]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $50$ $2500$ $117650$ $6250000$ $282475250$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $8$ $50$ $344$ $2598$ $16808$ $117650$ $823544$ $5755198$ $40353608$ $282475250$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 9 curves (of which all are hyperelliptic):

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 \(\Q(i, \sqrt{14})\).
Endomorphism algebra over $\overline{\F}_{7}$
The base change of $A$ to $\F_{7^{4}}$ is 1.2401.du 2 and its endomorphism algebra is $\mathrm{M}_{2}(B)$, where $B$ is the quaternion algebra over \(\Q\) ramified at $7$ and $\infty$.
Remainder of endomorphism lattice by field

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.7.a_ao$8$(not in LMFDB)
2.7.a_o$8$(not in LMFDB)
2.7.a_ah$24$(not in LMFDB)

Below is a list of all twists of this isogeny class.

TwistExtension degreeCommon base change
2.7.a_ao$8$(not in LMFDB)
2.7.a_o$8$(not in LMFDB)
2.7.a_ah$24$(not in LMFDB)
2.7.a_h$24$(not in LMFDB)