Properties

Label 2.41.ai_x
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:  $1 - 8 x + 23 x^{2} - 328 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.0481100458561$, $\pm0.618556620811$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\zeta_{12})\)
Galois group:  $C_2^2$
Jacobians:  $20$
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1369$ $2794129$ $4685402500$ $7976346967849$ $13423232938730809$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $34$ $1664$ $67978$ $2822724$ $115861154$ $4749934358$ $194753391314$ $7984928807044$ $327381919270138$ $13422659102962304$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 20 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.ase 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.i_x$2$(not in LMFDB)
2.41.q_fq$3$(not in LMFDB)
2.41.ak_ch$4$(not in LMFDB)

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

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