Properties

Label 2.71.j_ge
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 yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 + 3 x + 71 x^{2} )( 1 + 6 x + 71 x^{2} )$
  $1 + 9 x + 160 x^{2} + 639 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.556968285566$, $\pm0.615871442562$
Angle rank:  $2$ (numerical)
Jacobians:  $40$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $5850$ $26640900$ $127502505000$ $645530959101600$ $3255511666751808750$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $81$ $5281$ $356238$ $25402921$ $1804377951$ $128100213178$ $9095111056161$ $645753573694321$ $45848501088886818$ $3255243547057117801$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 40 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.d $\times$ 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:

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.aj_ge$2$(not in LMFDB)
2.71.ad_eu$2$(not in LMFDB)
2.71.d_eu$2$(not in LMFDB)