Properties

Label 2.23.am_cy
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:  $1 - 12 x + 76 x^{2} - 276 x^{3} + 529 x^{4}$
Frobenius angles:  $\pm0.156924629149$, $\pm0.379300706967$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-50 +12 \sqrt{6}})\)
Galois group:  $D_{4}$
Jacobians:  $12$
Isomorphism classes:  12
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $318$ $284292$ $150246414$ $78411145104$ $41421021299598$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $12$ $538$ $12348$ $280198$ $6435492$ $148044058$ $3404991252$ $78311930686$ $1801154110284$ $41426498189818$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 12 curves (of which all are hyperelliptic):

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

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 \(\Q(\sqrt{-50 +12 \sqrt{6}})\).

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.m_cy$2$(not in LMFDB)