Properties

Label 2.11.ac_m
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:  $1 - 2 x + 12 x^{2} - 22 x^{3} + 121 x^{4}$
Frobenius angles:  $\pm0.274452218988$, $\pm0.613561676632$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-8 +2 \sqrt{11}})\)
Galois group:  $D_{4}$
Jacobians:  $14$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $110$ $17380$ $1767590$ $217250000$ $26114827750$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $10$ $142$ $1330$ $14838$ $162150$ $1768942$ $19473310$ $214363038$ $2357931850$ $25937355102$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 14 curves (of which all are hyperelliptic):

  • $y^2=2 x^6+5 x^5+8 x^4+x^3+4 x^2+6 x+8$
  • $y^2=9 x^6+2 x^5+9 x^4+7 x^2+x+10$
  • $y^2=2 x^6+4 x^5+10 x^3+2 x^2+2 x+1$
  • $y^2=x^6+6 x^5+10 x^4+10 x^3+4 x^2+9 x+6$
  • $y^2=8 x^6+5 x^5+6 x^4+10 x^3+9 x^2+5 x+10$
  • $y^2=4 x^5+x^4+3 x^3+4 x^2+2 x+3$
  • $y^2=7 x^6+6 x^5+5 x^4+9 x^3+4 x^2+6 x+7$
  • $y^2=2 x^6+9 x^5+10 x^3+6 x^2+1$
  • $y^2=9 x^6+9 x^5+10 x^4+6 x^3+5 x^2+x+2$
  • $y^2=7 x^6+x^5+8 x^4+4 x^3+10 x^2+6 x+8$
  • $y^2=3 x^6+10 x^3+8 x^2+5 x+2$
  • $y^2=7 x^6+2 x^5+4 x^4+7 x^3+10 x^2+4 x+9$
  • $y^2=3 x^6+7 x^5+7 x^3+3 x^2+8 x+2$
  • $y^2=2 x^6+5 x^5+10 x^4+3 x^3+8 x^2+7 x+8$

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 \(\Q(\sqrt{-8 +2 \sqrt{11}})\).

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.c_m$2$2.121.u_lm