Properties

Label 2.11.c_k
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:  $1 + 2 x + 10 x^{2} + 22 x^{3} + 121 x^{4}$
Frobenius angles:  $\pm0.371505900167$, $\pm0.744291643071$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-30 +2 \sqrt{13}})\)
Galois group:  $D_{4}$
Jacobians:  $18$
Isomorphism classes:  24
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $156$ $16848$ $1789164$ $218080512$ $25738736556$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $14$ $138$ $1346$ $14894$ $159814$ $1769274$ $19496890$ $214359070$ $2358050270$ $25937280618$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 18 curves (of which all are hyperelliptic):

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

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 \(\Q(\sqrt{-30 +2 \sqrt{13}})\).

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.ac_k$2$2.121.q_ju