Properties

Label 2.67.ai_cn
Base field $\F_{67}$
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:  $\F_{67}$
Dimension:  $2$
L-polynomial:  $1 - 8 x + 65 x^{2} - 536 x^{3} + 4489 x^{4}$
Frobenius angles:  $\pm0.200813477949$, $\pm0.603291390978$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-167 +8 \sqrt{85}})\)
Galois group:  $D_{4}$
Jacobians:  $136$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4011$ $20452089$ $90290241216$ $406166400355401$ $1823036108219717811$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $60$ $4556$ $300204$ $20156020$ $1350271980$ $90458642342$ $6060709279188$ $406067698772644$ $27206534197365588$ $1822837799166565436$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 136 curves (of which all are hyperelliptic):

  • $y^2=66 x^6+66 x^5+62 x^4+44 x^3+53 x^2+55 x+57$
  • $y^2=58 x^6+44 x^5+41 x^4+61 x^3+57 x^2+x+36$
  • $y^2=42 x^6+42 x^5+40 x^4+41 x^3+x^2+5 x+65$
  • $y^2=52 x^6+51 x^4+x^3+58 x^2+59 x+49$
  • $y^2=54 x^6+x^5+29 x^4+46 x^3+38 x^2+64 x+32$
  • $y^2=29 x^6+66 x^5+60 x^3+46 x^2+17 x+43$
  • $y^2=43 x^6+50 x^5+49 x^4+60 x^3+11 x^2+41 x+5$
  • $y^2=63 x^6+61 x^5+50 x^4+23 x^3+8 x^2+48 x+47$
  • $y^2=27 x^6+23 x^5+6 x^4+48 x^3+6 x^2+59 x+9$
  • $y^2=23 x^6+38 x^5+44 x^4+9 x^3+6 x^2+64 x+61$
  • $y^2=52 x^6+62 x^5+11 x^4+48 x^3+19 x^2+5 x+38$
  • $y^2=14 x^6+37 x^5+31 x^4+25 x^3+5 x^2+17 x+32$
  • $y^2=59 x^6+18 x^5+17 x^4+4 x^2+43 x+12$
  • $y^2=50 x^6+51 x^5+5 x^4+53 x^3+45 x^2+4 x+39$
  • $y^2=57 x^6+36 x^5+30 x^4+24 x^3+30 x^2+2 x+39$
  • $y^2=50 x^6+22 x^5+50 x^4+37 x^3+38 x^2+49 x+53$
  • $y^2=63 x^6+44 x^5+53 x^4+5 x^3+34 x^2+55 x+58$
  • $y^2=61 x^6+63 x^5+36 x^4+38 x^3+27 x^2+41 x+35$
  • $y^2=10 x^6+25 x^5+21 x^4+60 x^3+40 x^2+59 x+40$
  • $y^2=18 x^6+59 x^5+7 x^4+23 x^3+62 x^2+57 x+23$
  • and 116 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{67}$.

Endomorphism algebra over $\F_{67}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-167 +8 \sqrt{85}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.67.i_cn$2$(not in LMFDB)