Properties

Label 2.41.c_cg
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:  $( 1 - 4 x + 41 x^{2} )( 1 + 6 x + 41 x^{2} )$
  $1 + 2 x + 58 x^{2} + 82 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.398884665197$, $\pm0.655213070720$
Angle rank:  $2$ (numerical)
Jacobians:  $106$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1824$ $3020544$ $4743540000$ $7985641734144$ $13421778966698784$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $44$ $1794$ $68828$ $2826014$ $115848604$ $4749924258$ $194755211884$ $7984933991614$ $327381889995788$ $13422659116361154$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 106 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.ae $\times$ 1.41.g and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.41.ak_ec$2$(not in LMFDB)
2.41.ac_cg$2$(not in LMFDB)
2.41.k_ec$2$(not in LMFDB)