Properties

Label 2.61.az_kn
Base field $\F_{61}$
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:  $\F_{61}$
Dimension:  $2$
L-polynomial:  $1 - 25 x + 273 x^{2} - 1525 x^{3} + 3721 x^{4}$
Frobenius angles:  $\pm0.104181476439$, $\pm0.273280674769$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-330 +50 \sqrt{21}})\)
Galois group:  $D_{4}$
Jacobians:  $8$
Isomorphism classes:  8
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $2445$ $13557525$ $51582822705$ $191779339197525$ $713366139840738000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $37$ $3643$ $227257$ $13851043$ $844623802$ $51520355323$ $3142741760797$ $191707313898883$ $11694146277548617$ $713342914465733398$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 8 curves (of which all are hyperelliptic):

  • $y^2=28 x^6+36 x^5+3 x^4+46 x^3+52 x^2+39 x+32$
  • $y^2=48 x^6+5 x^5+41 x^4+32 x^3+13 x^2+38 x+29$
  • $y^2=48 x^6+41 x^5+29 x^4+57 x^3+32 x^2+35 x+35$
  • $y^2=60 x^6+24 x^5+57 x^4+6 x^3+27 x^2+14 x+51$
  • $y^2=26 x^6+17 x^5+31 x^4+12 x^3+57 x^2+27 x+58$
  • $y^2=37 x^6+18 x^5+20 x^4+10 x^3+57 x^2+51 x+7$
  • $y^2=33 x^6+20 x^5+39 x^4+25 x^3+52 x^2+4 x+8$
  • $y^2=10 x^6+29 x^5+57 x^4+39 x^3+50 x^2+31 x+36$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61}$.

Endomorphism algebra over $\F_{61}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-330 +50 \sqrt{21}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.61.z_kn$2$(not in LMFDB)