Properties

Label 2.89.a_abv
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:  $( 1 - 15 x + 89 x^{2} )( 1 + 15 x + 89 x^{2} )$
  $1 - 47 x^{2} + 7921 x^{4}$
Frobenius angles:  $\pm0.207471636293$, $\pm0.792528363707$
Angle rank:  $1$ (numerical)
Jacobians:  $735$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7875$ $62015625$ $496982304000$ $3938299847015625$ $31181719919104321875$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $90$ $7828$ $704970$ $62769508$ $5584059450$ $496983317038$ $44231334895530$ $3936588684953668$ $350356403707485210$ $31181719908242460148$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 735 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{89^{2}}$.

Endomorphism algebra over $\F_{89}$
The isogeny class factors as 1.89.ap $\times$ 1.89.p 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 $\overline{\F}_{89}$
The base change of $A$ to $\F_{89^{2}}$ is 1.7921.abv 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-131}) \)$)$

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.abe_pn$2$(not in LMFDB)
2.89.be_pn$2$(not in LMFDB)
2.89.a_bv$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.89.abe_pn$2$(not in LMFDB)
2.89.be_pn$2$(not in LMFDB)
2.89.a_bv$4$(not in LMFDB)
2.89.ap_fg$6$(not in LMFDB)
2.89.p_fg$6$(not in LMFDB)