Properties

Label 2.89.i_hm
Base field $\F_{89}$
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:  $\F_{89}$
Dimension:  $2$
L-polynomial:  $( 1 + 4 x + 89 x^{2} )^{2}$
  $1 + 8 x + 194 x^{2} + 712 x^{3} + 7921 x^{4}$
Frobenius angles:  $\pm0.567997546099$, $\pm0.567997546099$
Angle rank:  $1$ (numerical)
Jacobians:  $60$
Cyclic group of points:    no
Non-cyclic primes:   $2, 47$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $8836$ $65351056$ $495568129156$ $3935283749785600$ $31183182579809491396$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $98$ $8246$ $702962$ $62721438$ $5584321378$ $496982094806$ $44231308368562$ $3936588840267838$ $350356405930122338$ $31181719917999282806$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 60 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{89}$.

Endomorphism algebra over $\F_{89}$
The isogeny class factors as 1.89.e 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-85}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.89.ai_hm$2$(not in LMFDB)
2.89.a_gg$2$(not in LMFDB)
2.89.ae_acv$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.89.ai_hm$2$(not in LMFDB)
2.89.a_gg$2$(not in LMFDB)
2.89.ae_acv$3$(not in LMFDB)
2.89.a_agg$4$(not in LMFDB)
2.89.e_acv$6$(not in LMFDB)