Abelian variety isogeny class 1.256.q over $\F_{2^{8}}$

• Label: 1.256.q
• Base field: $\F_{2^{8}}$
• Dimension: $1$
• $p$-rank: $0$
• Ordinary: no
• Supersingular: yes
• Simple: yes
• Geometrically simple: yes
• Primitive: yes
• Principally polarizable: yes
• Contains a Jacobian: yes

Invariants

Base field:	$\F_{2^{8}}$
Dimension:	$1$
L-polynomial:	$1 + 16 x + 256 x^{2}$
Frobenius angles:	$\pm0.666666666667$
Angle rank:	$0$ (numerical)
Number field:	\(\Q(\sqrt{-3}) \)
Galois group:	$C_2$
Jacobians:	$2$

This isogeny class is simple and 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:	$[1/2, 1/2]$

Point counts

Point counts of the abelian variety

$r$	$1$	$2$	$3$	$4$	$5$
$A(\F_{q^r})$	$273$	$65793$	$16769025$	$4295032833$	$1099512676353$

Point counts of the curve

$r$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$	$9$	$10$
$C(\F_{q^r})$	$273$	$65793$	$16769025$	$4295032833$	$1099512676353$	$281474943156225$	$72057594306363393$	$18446744078004518913$	$4722366482732206260225$	$1208925819615728686333953$

Jacobians and polarizations

This isogeny class contains the Jacobians of 2 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{2^{24}}$.

Endomorphism algebra over $\F_{2^{8}}$

The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-3}) \).

Endomorphism algebra over $\overline{\F}_{2^{8}}$

The base change of $A$ to $\F_{2^{24}}$ is the simple isogeny class 1.16777216.amdc and its endomorphism algebra is the quaternion algebra over \(\Q\) ramified at $2$ and $\infty$.

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

Twist	Extension degree	Common base change
1.256.aq	$2$	(not in LMFDB)
1.256.abg	$3$	(not in LMFDB)
1.256.bg	$6$	(not in LMFDB)