Properties

Label 2.23.a_be
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:  $( 1 - 4 x + 23 x^{2} )( 1 + 4 x + 23 x^{2} )$
  $1 + 30 x^{2} + 529 x^{4}$
Frobenius angles:  $\pm0.363071407864$, $\pm0.636928592136$
Angle rank:  $1$ (numerical)
Jacobians:  $77$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $560$ $313600$ $148015280$ $78400000000$ $41426506074800$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $24$ $590$ $12168$ $280158$ $6436344$ $147994670$ $3404825448$ $78312054718$ $1801152661464$ $41426500935950$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 77 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{23^{2}}$.

Endomorphism algebra over $\F_{23}$
The isogeny class factors as 1.23.ae $\times$ 1.23.e 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 $\overline{\F}_{23}$
The base change of $A$ to $\F_{23^{2}}$ is 1.529.be 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-19}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.23.ai_ck$2$(not in LMFDB)
2.23.i_ck$2$(not in LMFDB)
2.23.a_abe$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.23.ai_ck$2$(not in LMFDB)
2.23.i_ck$2$(not in LMFDB)
2.23.a_abe$4$(not in LMFDB)
2.23.ae_ah$6$(not in LMFDB)
2.23.e_ah$6$(not in LMFDB)