Properties

Label 2.2.a_d
Base field $\F_{2}$
Dimension $2$
$p$-rank $2$
Ordinary Yes
Supersingular No
Simple No
Geometrically simple No
Primitive Yes
Principally polarizable Yes
Contains a Jacobian No

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Invariants

Base field:  $\F_{2}$
Dimension:  $2$
L-polynomial:  $( 1 - x + 2 x^{2} )( 1 + x + 2 x^{2} )$
Frobenius angles:  $\pm0.384973271919$, $\pm0.615026728081$
Angle rank:  $1$ (numerical)
Jacobians:  0

This isogeny class is not simple.

Newton polygon

This isogeny class is ordinary.

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

Point counts

This isogeny class is principally polarizable, but does not contain a Jacobian.

Point counts of the abelian variety

$r$ 1 2 3 4 5 6 7 8 9 10
$A(\F_{q^r})$ 8 64 56 256 968 3136 16472 82944 263144 937024

Point counts of the (virtual) curve

$r$ 1 2 3 4 5 6 7 8 9 10
$C(\F_{q^r})$ 3 11 9 15 33 47 129 319 513 911

Decomposition and endomorphism algebra

Endomorphism algebra over $\F_{2}$
The isogeny class factors as 1.2.ab $\times$ 1.2.b and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:
Endomorphism algebra over $\overline{\F}_{2}$
The base change of $A$ to $\F_{2^{2}}$ is 1.4.d 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-7}) \)$)$
All geometric endomorphisms are defined over $\F_{2^{2}}$.

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.
TwistExtension DegreeCommon base change
2.2.ac_f$2$2.4.g_r
2.2.c_f$2$2.4.g_r
2.2.a_ad$4$2.16.ac_bh
Below is a list of all twists of this isogeny class.
TwistExtension DegreeCommon base change
2.2.ac_f$2$2.4.g_r
2.2.c_f$2$2.4.g_r
2.2.a_ad$4$2.16.ac_bh
2.2.ab_ab$6$2.64.as_ib
2.2.b_ab$6$2.64.as_ib