Properties

Label 2.23.a_ag
Base field $\F_{23}$
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:  $\F_{23}$
Dimension:  $2$
L-polynomial:  $1 - 6 x^{2} + 529 x^{4}$
Frobenius angles:  $\pm0.229181340406$, $\pm0.770818659594$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-10}, \sqrt{13})\)
Galois group:  $C_2^2$
Jacobians:  $22$
Isomorphism classes:  40
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $524$ $274576$ $148045196$ $78884586496$ $41426503381964$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $24$ $518$ $12168$ $281886$ $6436344$ $148054502$ $3404825448$ $78310015678$ $1801152661464$ $41426495550278$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 22 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 endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-10}, \sqrt{13})\).
Endomorphism algebra over $\overline{\F}_{23}$
The base change of $A$ to $\F_{23^{2}}$ is 1.529.ag 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-130}) \)$)$

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.a_g$4$(not in LMFDB)