Properties

Label 2.71.r_ig
Base field $\F_{71}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian no

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Invariants

Base field:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 + 8 x + 71 x^{2} )( 1 + 9 x + 71 x^{2} )$
  $1 + 17 x + 214 x^{2} + 1207 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.657448017853$, $\pm0.679331255589$
Angle rank:  $2$ (numerical)
Jacobians:  $0$
Isomorphism classes:  32
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is not simple, primitive, ordinary, and not supersingular. It is principally polarizable.

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $2$
Slopes:  $[0, 0, 1, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6480$ $26127360$ $127250585280$ $646016847114240$ $3255387437923182000$

Point counts of the (virtual) curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $89$ $5181$ $355532$ $25422041$ $1804309099$ $128098883358$ $9095126396389$ $645753576446161$ $45848499903587012$ $3255243554720630901$

Jacobians and polarizations

This isogeny class is principally polarizable, but does not contain a Jacobian.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71}$.

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.i $\times$ 1.71.j 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
2.71.ar_ig$2$(not in LMFDB)
2.71.ab_cs$2$(not in LMFDB)
2.71.b_cs$2$(not in LMFDB)