Properties

Label 1.128.l
Base Field $\F_{2^{7}}$
Dimension $1$
Ordinary Yes
$p$-rank $1$
Principally polarizable Yes
Contains a Jacobian Yes

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Invariants

Base field:  $\F_{2^{7}}$
Dimension:  $1$
L-polynomial:  $1 + 11 x + 128 x^{2}$
Frobenius angles:  $\pm0.661594006177$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-391}) \)
Galois group:  $C_2$
Jacobians:  14

This isogeny class is simple and geometrically simple.

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $1$
Slopes:  $[0, 1]$

Point counts

This isogeny class contains the Jacobians of 14 curves, and hence is principally polarizable:

Point counts of the abelian variety

$r$ 1 2 3 4 5 6 7 8 9 10
$A(\F_{q^r})$ 140 16520 2094260 268450000 34359948700 4398042335960 562949972425540 72057594363300000 9223372030843142060 1180591620741891650600

Point counts of the curve

$r$ 1 2 3 4 5 6 7 8 9 10
$C(\F_{q^r})$ 140 16520 2094260 268450000 34359948700 4398042335960 562949972425540 72057594363300000 9223372030843142060 1180591620741891650600

Decomposition and endomorphism algebra

Endomorphism algebra over $\F_{2^{7}}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-391}) \).
All geometric endomorphisms are defined over $\F_{2^{7}}$.

Base change

This is a primitive isogeny class.

Twists

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