Properties

Label 2.11.f_u
Base field $\F_{11}$
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:  $\F_{11}$
Dimension:  $2$
L-polynomial:  $1 + 5 x + 20 x^{2} + 55 x^{3} + 121 x^{4}$
Frobenius angles:  $\pm0.482125936541$, $\pm0.800479701061$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-118 +10 \sqrt{33}})\)
Galois group:  $D_{4}$
Jacobians:  $4$
Isomorphism classes:  4
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $202$ $16564$ $1760632$ $213741856$ $25772846902$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $17$ $137$ $1322$ $14601$ $160027$ $1776242$ $19487737$ $214323793$ $2357978462$ $25937375177$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 4 curves (of which all are hyperelliptic):

  • $y^2=3 x^6+x^5+7 x^3+7 x^2+6 x+9$
  • $y^2=9 x^5+3 x^4+7 x^3+7 x^2+2 x+9$
  • $y^2=4 x^6+2 x^5+2 x^4+8 x^3+10 x^2+9 x+8$
  • $y^2=10 x^6+4 x^5+2 x^4+6 x^3+10 x^2+3 x+3$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{11}$.

Endomorphism algebra over $\F_{11}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-118 +10 \sqrt{33}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.11.af_u$2$2.121.p_do