Properties

Label 2.67.a_de
Base field $\F_{67}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{67}$
Dimension:  $2$
L-polynomial:  $1 + 82 x^{2} + 4489 x^{4}$
Frobenius angles:  $\pm0.354805366095$, $\pm0.645194633905$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-6}, \sqrt{13})\)
Galois group:  $C_2^2$
Jacobians:  $424$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3$

This isogeny class is simple but not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4572$ $20903184$ $90457829244$ $406158564197376$ $1822837804145664732$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $4654$ $300764$ $20155630$ $1350125108$ $90457276318$ $6060711605324$ $406067748000094$ $27206534396294948$ $1822837803739568014$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 424 curves (of which all are hyperelliptic):

  • $y^2=25 x^6+66 x^5+63 x^4+35 x^3+60 x^2+4 x+12$
  • $y^2=50 x^6+65 x^5+59 x^4+3 x^3+53 x^2+8 x+24$
  • $y^2=7 x^6+23 x^5+30 x^4+40 x^3+48 x^2+55 x+62$
  • $y^2=14 x^6+46 x^5+60 x^4+13 x^3+29 x^2+43 x+57$
  • $y^2=26 x^6+13 x^5+66 x^4+63 x^3+29 x^2+53 x+35$
  • $y^2=52 x^6+26 x^5+65 x^4+59 x^3+58 x^2+39 x+3$
  • $y^2=53 x^6+51 x^5+2 x^4+59 x^3+63 x^2+10 x+42$
  • $y^2=39 x^6+35 x^5+4 x^4+51 x^3+59 x^2+20 x+17$
  • $y^2=4 x^6+59 x^5+26 x^4+9 x^3+48 x^2+7 x+6$
  • $y^2=8 x^6+51 x^5+52 x^4+18 x^3+29 x^2+14 x+12$
  • $y^2=48 x^6+40 x^5+65 x^4+25 x^3+38 x^2+6 x+52$
  • $y^2=29 x^6+13 x^5+63 x^4+50 x^3+9 x^2+12 x+37$
  • $y^2=22 x^6+15 x^5+38 x^4+x^3+20 x^2+29 x$
  • $y^2=44 x^6+30 x^5+9 x^4+2 x^3+40 x^2+58 x$
  • $y^2=62 x^6+63 x^5+8 x^4+15 x^3+14 x^2+3 x+43$
  • $y^2=57 x^6+59 x^5+16 x^4+30 x^3+28 x^2+6 x+19$
  • $y^2=38 x^6+40 x^5+17 x^4+42 x^3+16 x^2+24 x+58$
  • $y^2=9 x^6+13 x^5+34 x^4+17 x^3+32 x^2+48 x+49$
  • $y^2=21 x^6+46 x^5+22 x^4+65 x^3+30 x^2+21 x+33$
  • $y^2=42 x^6+25 x^5+44 x^4+63 x^3+60 x^2+42 x+66$
  • and 404 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{67^{2}}$.

Endomorphism algebra over $\F_{67}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-6}, \sqrt{13})\).
Endomorphism algebra over $\overline{\F}_{67}$
The base change of $A$ to $\F_{67^{2}}$ is 1.4489.de 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-78}) \)$)$

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.a_ade$4$(not in LMFDB)