Properties

Label 2.71.ae_fq
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:  $( 1 - 2 x + 71 x^{2} )^{2}$
  $1 - 4 x + 146 x^{2} - 284 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.462134322676$, $\pm0.462134322676$
Angle rank:  $1$ (numerical)
Jacobians:  $50$
Cyclic group of points:    no
Non-cyclic primes:   $2, 5, 7$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4900$ $26832400$ $128400388900$ $645298183398400$ $3255071787033062500$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $5318$ $358748$ $25393758$ $1804134148$ $128101366118$ $9095129082268$ $645753472257598$ $45848499966877508$ $3255243553694897798$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 50 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.ac 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-70}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.71.a_fi$2$(not in LMFDB)
2.71.e_fq$2$(not in LMFDB)
2.71.c_acp$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.71.a_fi$2$(not in LMFDB)
2.71.e_fq$2$(not in LMFDB)
2.71.c_acp$3$(not in LMFDB)
2.71.a_afi$4$(not in LMFDB)
2.71.ac_acp$6$(not in LMFDB)