Properties

Label 2.41.ac_df
Base field $\F_{41}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
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:  $( 1 - x + 41 x^{2} )^{2}$
  $1 - 2 x + 83 x^{2} - 82 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.475118844265$, $\pm0.475118844265$
Angle rank:  $1$ (numerical)
Jacobians:  $7$
Cyclic group of points:    no
Non-cyclic primes:   $41$

This isogeny class is not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1681$ $3108169$ $4767073936$ $7966861888969$ $13420759335696001$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $40$ $1844$ $69166$ $2819364$ $115839800$ $4750350158$ $194755192280$ $7984916064964$ $327381887575486$ $13422659639064404$

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 $\F_{41}$.

Endomorphism algebra over $\F_{41}$
The isogeny class factors as 1.41.ab 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-163}) \)$)$

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.a_dd$2$(not in LMFDB)
2.41.c_df$2$(not in LMFDB)
2.41.b_abo$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.a_dd$2$(not in LMFDB)
2.41.c_df$2$(not in LMFDB)
2.41.b_abo$3$(not in LMFDB)
2.41.a_add$4$(not in LMFDB)
2.41.ab_abo$6$(not in LMFDB)