Properties

Label 4.2.ae_g_ae_c
Base field $\F_{2}$
Dimension $4$
$p$-rank $0$
Ordinary no
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Contains a Jacobian no

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Invariants

Base field:  $\F_{2}$
Dimension:  $4$
L-polynomial:  $1 - 4 x + 6 x^{2} - 4 x^{3} + 2 x^{4} - 8 x^{5} + 24 x^{6} - 32 x^{7} + 16 x^{8}$
Frobenius angles:  $\pm0.0377785699724$, $\pm0.148391828106$, $\pm0.398391828106$, $\pm0.787778569972$
Angle rank:  $2$ (numerical)
Number field:  8.0.18939904.2
Galois group:  $D_4\times C_2$
Jacobians:  $0$
Isomorphism classes:  2

This isogeny class is simple and geometrically simple, primitive, not ordinary, and not supersingular.

Newton polygon

$p$-rank:  $0$
Slopes:  $[1/4, 1/4, 1/4, 1/4, 3/4, 3/4, 3/4, 3/4]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1$ $97$ $2689$ $67609$ $457601$

Point counts of the (virtual) curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $-1$ $1$ $5$ $17$ $9$ $73$ $153$ $273$ $545$ $881$

Jacobians and polarizations

This isogeny class does not contain a Jacobian, and it is unknown whether it is principally polarizable.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{2^{8}}$.

Endomorphism algebra over $\F_{2}$
The endomorphism algebra of this simple isogeny class is 8.0.18939904.2.
Endomorphism algebra over $\overline{\F}_{2}$
The base change of $A$ to $\F_{2^{8}}$ is the simple isogeny class 4.256.q_ds_glk_jitk and its endomorphism algebra is the quaternion algebra over 4.0.1088.2 with the following ramification data at primes above $2$, and unramified at all archimedean places:
$v$ ($ 2 $,\( \pi \)) ($ 2 $,\( \pi + 1 \))
$\operatorname{inv}_v$$1/2$$1/2$
where $\pi$ is a root of $x^{4} - 2x^{3} + 5x^{2} - 4x + 2$.
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
4.2.e_g_e_c$2$4.4.ae_i_ai_e
4.2.a_c_ae_c$4$(not in LMFDB)
4.2.a_c_e_c$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
4.2.e_g_e_c$2$4.4.ae_i_ai_e
4.2.a_c_ae_c$4$(not in LMFDB)
4.2.a_c_e_c$4$(not in LMFDB)
4.2.a_c_ae_c$8$(not in LMFDB)
4.2.a_c_e_c$8$(not in LMFDB)
4.2.e_g_e_c$8$(not in LMFDB)
4.2.a_ae_a_k$16$(not in LMFDB)
4.2.a_e_a_k$16$(not in LMFDB)