Abelian variety isogeny class 2.9.ah_bb over $\F_{3^{2}}$

• Label: 2.9.ah_bb
• Base field: $\F_{3^{2}}$
• Dimension: $2$
• $p$-rank: $1$
• Ordinary: no
• Supersingular: no
• Simple: yes
• Geometrically simple: yes
• Primitive: yes
• Principally polarizable: yes
• Contains a Jacobian: yes

Invariants

Base field:	$\F_{3^{2}}$
Dimension:	$2$
L-polynomial:	$1 - 7 x + 27 x^{2} - 63 x^{3} + 81 x^{4}$
Frobenius angles:	$\pm0.154979380638$, $\pm0.408713257520$
Angle rank:	$2$ (numerical)
Number field:	4.0.4901.1
Galois group:	$D_{4}$
Jacobians:	$2$

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

Newton polygon

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

Point counts

Point counts of the abelian variety

$r$	$1$	$2$	$3$	$4$	$5$
$A(\F_{q^r})$	$39$	$6981$	$558207$	$43009941$	$3480111024$

Point counts of the curve

$r$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$	$9$	$10$
$C(\F_{q^r})$	$3$	$87$	$765$	$6555$	$58938$	$532647$	$4791153$	$43064979$	$387412335$	$3486652302$

Jacobians and polarizations

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

• $y^2=(2a+1)x^6+x^4+(a+2)x^3+(2a+1)x+2a+1$
• $y^2=ax^6+x^4+2ax^3+ax+a$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{3^{2}}$.

Endomorphism algebra over $\F_{3^{2}}$

The endomorphism algebra of this simple isogeny class is 4.0.4901.1.

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
2.9.h_bb	$2$	2.81.f_j