Properties

Label 2.41.k_ch
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:  $1 + 10 x + 59 x^{2} + 410 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.451889954144$, $\pm0.881443379189$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\zeta_{12})\)
Galois group:  $C_2^2$
Jacobians:  $70$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $2161$ $2854681$ $4781999104$ $7976346967849$ $13420232445766801$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $52$ $1700$ $69382$ $2822724$ $115835252$ $4750274126$ $194754283412$ $7984928807044$ $327381863616982$ $13422659517342500$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 70 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 \(\Q(\zeta_{12})\).
Endomorphism algebra over $\overline{\F}_{41}$
The base change of $A$ to $\F_{41^{3}}$ is 1.68921.iw 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1}) \)$)$

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.ak_ch$2$(not in LMFDB)
2.41.au_ha$3$(not in LMFDB)
2.41.ai_x$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.ak_ch$2$(not in LMFDB)
2.41.au_ha$3$(not in LMFDB)
2.41.ai_x$4$(not in LMFDB)
2.41.i_x$4$(not in LMFDB)
2.41.a_as$6$(not in LMFDB)
2.41.u_ha$6$(not in LMFDB)
2.41.as_gg$12$(not in LMFDB)
2.41.aq_fq$12$(not in LMFDB)
2.41.ac_c$12$(not in LMFDB)
2.41.a_s$12$(not in LMFDB)
2.41.c_c$12$(not in LMFDB)
2.41.i_x$12$(not in LMFDB)
2.41.q_fq$12$(not in LMFDB)
2.41.s_gg$12$(not in LMFDB)
2.41.a_adc$24$(not in LMFDB)
2.41.a_dc$24$(not in LMFDB)