Properties

Label 2.41.j_cp
Base field $\F_{41}$
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:  $\F_{41}$
Dimension:  $2$
L-polynomial:  $1 + 9 x + 67 x^{2} + 369 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.464202515922$, $\pm0.803266490433$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-434 +18 \sqrt{141}})\)
Galois group:  $D_{4}$
Jacobians:  $76$
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $2127$ $2916117$ $4752077463$ $7983818025525$ $13418839314491952$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $51$ $1735$ $68949$ $2825371$ $115823226$ $4750328167$ $194754566841$ $7984920414931$ $327381930897759$ $13422659179649230$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 76 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41}$.

Endomorphism algebra over $\F_{41}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-434 +18 \sqrt{141}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.41.aj_cp$2$(not in LMFDB)