Properties

Label 2.19.ak_cb
Base Field $\F_{19}$
Dimension $2$
Ordinary Yes
$p$-rank $2$
Principally polarizable Yes
Contains a Jacobian Yes

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Invariants

Base field:  $\F_{19}$
Dimension:  $2$
L-polynomial:  $1 - 10 x + 53 x^{2} - 190 x^{3} + 361 x^{4}$
Frobenius angles:  $\pm0.114247126664$, $\pm0.432392726124$
Angle rank:  $2$ (numerical)
Number field:  4.0.1089600.1
Galois group:  $D_{4}$
Jacobians:  6

This isogeny class is simple and geometrically simple.

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $2$
Slopes:  $[0, 0, 1, 1]$

Point counts

This isogeny class contains the Jacobians of 6 curves, and hence is principally polarizable:

Point counts of the abelian variety

$r$ 1 2 3 4 5 6 7 8 9 10
$A(\F_{q^r})$ 215 132225 47189060 16909065225 6125993285375 2213858705619600 799103166028169735 288446246214898113225 104127369936118146687140 37589984877552646042640625

Point counts of the curve

$r$ 1 2 3 4 5 6 7 8 9 10
$C(\F_{q^r})$ 10 368 6880 129748 2474050 47057438 893979670 16983847588 322687758640 6131068120448

Decomposition and endomorphism algebra

Endomorphism algebra over $\F_{19}$
The endomorphism algebra of this simple isogeny class is 4.0.1089600.1.
All geometric endomorphisms are defined over $\F_{19}$.

Base change

This is a primitive isogeny class.

Twists

Below is a list of all twists of this isogeny class.
TwistExtension DegreeCommon base change
2.19.k_cb$2$(not in LMFDB)