Properties

Label 2.256.ach_caz
Base field $\F_{2^{8}}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{2^{8}}$
Dimension:  $2$
L-polynomial:  $1 - 59 x + 1377 x^{2} - 15104 x^{3} + 65536 x^{4}$
Frobenius angles:  $\pm0.0363747766709$, $\pm0.176437257411$
Angle rank:  $2$ (numerical)
Number field:  4.0.1665657.4
Galois group:  $D_{4}$

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

Newton polygon

This isogeny class is ordinary.

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

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $51751$ $4247566827$ $281358201468400$ $18446577982334005875$ $1208926029731150837928031$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $198$ $64810$ $16770255$ $4294928626$ $1099511818878$ $281474983726207$ $72057594060874158$ $18446744070823698466$ $4722366482761221803535$ $1208925819612092821932730$

Jacobians and polarizations

This isogeny class contains a Jacobian, and hence is principally polarizable.

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{2^{8}}$
The endomorphism algebra of this simple isogeny class is 4.0.1665657.4.

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.256.ch_caz$2$(not in LMFDB)