Properties

Label 2.41.ag_af
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:  $1 - 6 x - 5 x^{2} - 246 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.0114535959467$, $\pm0.678120262613$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-2}, \sqrt{-3})\)
Galois group:  $C_2^2$
Jacobians:  $7$
Isomorphism classes:  20
Cyclic group of points:    no
Non-cyclic primes:   $5$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1425$ $2748825$ $4678560000$ $7981403056425$ $13421045974760625$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $36$ $1636$ $67878$ $2824516$ $115842276$ $4749834958$ $194754036996$ $7984921130116$ $327381865781238$ $13422659272373476$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 7 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41^{3}}$.

Endomorphism algebra over $\F_{41}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-2}, \sqrt{-3})\).
Endomorphism algebra over $\overline{\F}_{41}$
The base change of $A$ to $\F_{41^{3}}$ is 1.68921.auc 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-2}) \)$)$

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.g_af$2$(not in LMFDB)
2.41.m_eo$3$(not in LMFDB)
2.41.am_eo$6$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.g_af$2$(not in LMFDB)
2.41.m_eo$3$(not in LMFDB)
2.41.am_eo$6$(not in LMFDB)
2.41.a_bu$6$(not in LMFDB)
2.41.a_abu$12$(not in LMFDB)
2.41.aq_ey$24$(not in LMFDB)
2.41.q_ey$24$(not in LMFDB)