Properties

Label 2.23.ad_bc
Base field $\F_{23}$
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:  $\F_{23}$
Dimension:  $2$
L-polynomial:  $( 1 - 6 x + 23 x^{2} )( 1 + 3 x + 23 x^{2} )$
  $1 - 3 x + 28 x^{2} - 69 x^{3} + 529 x^{4}$
Frobenius angles:  $\pm0.284877382774$, $\pm0.601257449372$
Angle rank:  $2$ (numerical)
Jacobians:  $48$
Cyclic group of points:    no
Non-cyclic primes:   $3$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $486$ $306180$ $148243608$ $78492304800$ $41466866711346$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $21$ $577$ $12186$ $280489$ $6442611$ $148012954$ $3404616285$ $78311090161$ $1801153934838$ $41426509798057$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 48 curves (of which all are hyperelliptic):

  • $y^2=7 x^6+14 x^5+6 x^4+12 x^3+14 x^2+6 x+5$
  • $y^2=5 x^6+6 x^5+16 x^4+15 x^3+13 x^2+19 x+13$
  • $y^2=19 x^6+19 x^5+12 x^4+12 x^3+17 x^2+x+18$
  • $y^2=15 x^6+20 x^5+7 x^4+15 x^3+x^2+19 x+9$
  • $y^2=2 x^5+3 x^4+2 x^3+21 x^2+20$
  • $y^2=x^6+15 x^4+15 x^3+3 x^2+21 x+22$
  • $y^2=4 x^6+21 x^5+10 x^4+10 x^3+10 x^2+20 x+14$
  • $y^2=8 x^6+12 x^5+9 x^4+10 x^2+17 x+12$
  • $y^2=3 x^6+7 x^5+3 x^4+16 x^3+18 x^2+16 x+11$
  • $y^2=3 x^6+4 x^5+17 x^4+17 x^3+17 x^2+21 x+4$
  • $y^2=14 x^6+11 x^5+17 x^4+5 x^3+20 x^2+4 x+14$
  • $y^2=9 x^6+12 x^5+3 x^4+9 x^3+21 x^2+16 x+7$
  • $y^2=3 x^6+15 x^5+8 x^4+20 x^3+12 x+13$
  • $y^2=13 x^6+15 x^5+2 x^4+11 x^3+7 x^2+20 x+16$
  • $y^2=8 x^6+22 x^5+11 x^4+11 x^3+8 x^2+4 x+7$
  • $y^2=16 x^6+22 x^5+4 x^4+22 x^3+15 x^2+8 x+20$
  • $y^2=5 x^6+12 x^5+14 x^4+3 x^3+12 x+1$
  • $y^2=7 x^6+5 x^5+15 x^4+22 x^3+18 x^2+8 x+16$
  • $y^2=14 x^6+3 x^5+6 x^4+7 x^3+17 x^2+22 x+3$
  • $y^2=12 x^6+2 x^5+20 x^4+19 x^3+22 x^2+4 x+1$
  • and 28 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{23}$
The isogeny class factors as 1.23.ag $\times$ 1.23.d and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

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.aj_cm$2$(not in LMFDB)
2.23.d_bc$2$(not in LMFDB)
2.23.j_cm$2$(not in LMFDB)