Properties

Label 2.41.a_abi
Base field $\F_{41}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{41}$
Dimension:  $2$
L-polynomial:  $1 - 34 x^{2} + 1681 x^{4}$
Frobenius angles:  $\pm0.181954780413$, $\pm0.818045219587$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-3}, \sqrt{29})\)
Galois group:  $C_2^2$
Jacobians:  $108$
Isomorphism classes:  240

This isogeny class is simple but not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1648$ $2715904$ $4750236400$ $7997403009024$ $13422659114687728$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $42$ $1614$ $68922$ $2830174$ $115856202$ $4750368558$ $194754273882$ $7984926799294$ $327381934393962$ $13422658919223054$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 108 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41^{2}}$.

Endomorphism algebra over $\F_{41}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-3}, \sqrt{29})\).
Endomorphism algebra over $\overline{\F}_{41}$
The base change of $A$ to $\F_{41^{2}}$ is 1.1681.abi 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-87}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.41.am_dl$3$(not in LMFDB)
2.41.m_dl$3$(not in LMFDB)
2.41.a_bi$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.am_dl$3$(not in LMFDB)
2.41.m_dl$3$(not in LMFDB)
2.41.a_bi$4$(not in LMFDB)
2.41.am_dl$6$(not in LMFDB)