Properties

Label 2.89.ak_hv
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

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Invariants

Base field:  $\F_{89}$
Dimension:  $2$
L-polynomial:  $( 1 - 5 x + 89 x^{2} )^{2}$
  $1 - 10 x + 203 x^{2} - 890 x^{3} + 7921 x^{4}$
Frobenius angles:  $\pm0.414628214971$, $\pm0.414628214971$
Angle rank:  $1$ (numerical)
Jacobians:  $45$
Cyclic group of points:    no
Non-cyclic primes:   $5, 17$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7225$ $65205625$ $498690192400$ $3935639447355625$ $31180094721808905625$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $80$ $8228$ $707390$ $62727108$ $5583768400$ $496981182638$ $44231360257360$ $3936588942152068$ $350356402132532270$ $31181719909947370148$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 45 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.af 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-331}) \)$)$

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.a_fx$2$(not in LMFDB)
2.89.k_hv$2$(not in LMFDB)
2.89.f_acm$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.89.a_fx$2$(not in LMFDB)
2.89.k_hv$2$(not in LMFDB)
2.89.f_acm$3$(not in LMFDB)
2.89.a_afx$4$(not in LMFDB)
2.89.af_acm$6$(not in LMFDB)