Properties

Label 2.71.g_fm
Base field $\F_{71}$
Dimension $2$
$p$-rank $1$
Ordinary no
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 + 71 x^{2} )( 1 + 6 x + 71 x^{2} )$
  $1 + 6 x + 142 x^{2} + 426 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.5$, $\pm0.615871442562$
Angle rank:  $1$ (numerical)
Jacobians:  $336$

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

Newton polygon

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

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $5616$ $26687232$ $127720897200$ $645468068044800$ $3255392089603972656$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $78$ $5290$ $356850$ $25400446$ $1804311678$ $128100587722$ $9095116785378$ $645753529914046$ $45848500660983150$ $3255243551449228330$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 336 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71^{2}}$.

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.a $\times$ 1.71.g and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:
Endomorphism algebra over $\overline{\F}_{71}$
The base change of $A$ to $\F_{71^{2}}$ is 1.5041.ec $\times$ 1.5041.fm. 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.ag_fm$2$(not in LMFDB)