Properties

Label 2.89.a_af
Base field $\F_{89}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
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:  $1 - 5 x^{2} + 7921 x^{4}$
Frobenius angles:  $\pm0.245528767401$, $\pm0.754471232599$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-173}, \sqrt{183})\)
Galois group:  $C_2^2$
Jacobians:  $286$
Cyclic group of points:    yes

This isogeny class is simple but not geometrically 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7917$ $62678889$ $496981409652$ $3938573969447481$ $31181719928402575077$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $90$ $7912$ $704970$ $62773876$ $5584059450$ $496981528342$ $44231334895530$ $3936588556316068$ $350356403707485210$ $31181719926838966552$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 286 curves (of which all are hyperelliptic):

  • $y^2=54 x^6+44 x^5+39 x^4+45 x^3+70 x^2+72 x+64$
  • $y^2=32 x^6+69 x^5+81 x^4+6 x^3+63 x^2+78 x+75$
  • $y^2=48 x^6+20 x^5+5 x^4+51 x^3+77 x^2+22 x+31$
  • $y^2=55 x^6+60 x^5+15 x^4+64 x^3+53 x^2+66 x+4$
  • $y^2=31 x^6+11 x^5+65 x^4+65 x^3+40 x^2+56 x+51$
  • $y^2=4 x^6+33 x^5+17 x^4+17 x^3+31 x^2+79 x+64$
  • $y^2=48 x^6+15 x^5+68 x^4+34 x^3+54 x^2+13$
  • $y^2=55 x^6+45 x^5+26 x^4+13 x^3+73 x^2+39$
  • $y^2=69 x^6+62 x^5+88 x^4+3 x^3+29 x^2+28 x+79$
  • $y^2=29 x^6+8 x^5+86 x^4+9 x^3+87 x^2+84 x+59$
  • $y^2=25 x^6+50 x^5+83 x^4+4 x^3+81 x^2+23 x+35$
  • $y^2=75 x^6+61 x^5+71 x^4+12 x^3+65 x^2+69 x+16$
  • $y^2=9 x^6+67 x^5+22 x^4+46 x^3+82 x^2+18 x+77$
  • $y^2=x^6+12 x^5+5 x^4+75 x^3+12 x^2+5 x+11$
  • $y^2=3 x^6+36 x^5+15 x^4+47 x^3+36 x^2+15 x+33$
  • $y^2=26 x^6+38 x^5+80 x^4+82 x^3+33 x^2+65 x+2$
  • $y^2=78 x^6+25 x^5+62 x^4+68 x^3+10 x^2+17 x+6$
  • $y^2=30 x^6+41 x^5+71 x^4+88 x^3+29 x^2+85 x+54$
  • $y^2=x^6+34 x^5+35 x^4+86 x^3+87 x^2+77 x+73$
  • $y^2=45 x^6+14 x^5+76 x^4+45 x^3+30 x^2+21 x+67$
  • and 266 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{89}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-173}, \sqrt{183})\).
Endomorphism algebra over $\overline{\F}_{89}$
The base change of $A$ to $\F_{89^{2}}$ is 1.7921.af 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-31659}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.89.a_f$4$(not in LMFDB)