Properties

Label 2.23.af_be
Base field $\F_{23}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{23}$
Dimension:  $2$
L-polynomial:  $1 - 5 x + 30 x^{2} - 115 x^{3} + 529 x^{4}$
Frobenius angles:  $\pm0.228884843756$, $\pm0.574244640662$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-254 +10 \sqrt{89}})\)
Galois group:  $D_{4}$
Jacobians:  $64$
Isomorphism classes:  64
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is simple and 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $440$ $299200$ $147799520$ $78420320000$ $41485920632200$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $19$ $565$ $12148$ $280233$ $6445569$ $148049470$ $3404672143$ $78310665393$ $1801152342844$ $41426494403325$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 64 curves (of which all are hyperelliptic):

  • $y^2=17 x^6+17 x^5+7 x^4+11 x^3+5 x^2+2 x+6$
  • $y^2=8 x^6+7 x^5+22 x^4+22 x^3+6 x^2+2 x+10$
  • $y^2=10 x^6+x^5+19 x^4+13 x^3+9 x^2+7 x+21$
  • $y^2=11 x^6+20 x^5+17 x^4+19 x^3+9 x^2+6 x+21$
  • $y^2=x^6+19 x^5+14 x^4+21 x^3+3 x^2+15 x+11$
  • $y^2=20 x^6+10 x^5+20 x^4+21 x^3+19 x^2+17 x+10$
  • $y^2=8 x^6+11 x^5+10 x^4+4 x^3+7 x^2+22 x+21$
  • $y^2=16 x^6+6 x^5+14 x^4+11 x^3+16 x^2+15 x+8$
  • $y^2=9 x^5+15 x^4+22 x^3+21 x^2+8 x$
  • $y^2=22 x^6+11 x^5+21 x^4+3 x^3+13 x^2+17 x+3$
  • $y^2=10 x^6+21 x^5+10 x^4+21 x^3+3 x^2+4 x+15$
  • $y^2=5 x^6+13 x^5+12 x^4+x^2+7 x+17$
  • $y^2=2 x^6+15 x^5+17 x^4+x^3+20 x^2+19 x$
  • $y^2=16 x^6+5 x^5+18 x^4+x^3+8 x^2+6 x+4$
  • $y^2=13 x^6+3 x^5+8 x^4+22 x^3+16 x^2+19 x+10$
  • $y^2=22 x^6+11 x^5+3 x^4+9 x^3+3 x^2+13 x+7$
  • $y^2=21 x^6+21 x^5+7 x^4+2 x^3+9 x^2+15 x$
  • $y^2=13 x^5+7 x^4+x^3+11 x^2+14 x+1$
  • $y^2=15 x^6+2 x^5+2 x^4+5 x^3+16 x^2+6 x+1$
  • $y^2=22 x^6+17 x^5+16 x^4+21 x^3+6 x^2+2 x+16$
  • and 44 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{23}$.

Endomorphism algebra over $\F_{23}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-254 +10 \sqrt{89}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.23.f_be$2$(not in LMFDB)