Properties

Label 2.163.abs_bfa
Base field $\F_{163}$
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:  $\F_{163}$
Dimension:  $2$
L-polynomial:  $( 1 - 24 x + 163 x^{2} )( 1 - 20 x + 163 x^{2} )$
  $1 - 44 x + 806 x^{2} - 7172 x^{3} + 26569 x^{4}$
Frobenius angles:  $\pm0.110906256499$, $\pm0.213555132351$
Angle rank:  $2$ (numerical)
Jacobians:  $90$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $20160$ $697374720$ $18754040652480$ $498338451704217600$ $13239725573807133508800$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $120$ $26246$ $4330440$ $705950062$ $115064395800$ $18755379372854$ $3057125327382120$ $498311414782454878$ $81224760534391959480$ $13239635967025336611686$

Jacobians and polarizations

This isogeny class contains the Jacobians of 90 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{163}$.

Endomorphism algebra over $\F_{163}$
The isogeny class factors as 1.163.ay $\times$ 1.163.au 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
2.163.ae_afy$2$(not in LMFDB)
2.163.e_afy$2$(not in LMFDB)
2.163.bs_bfa$2$(not in LMFDB)