Properties

Label 2.67.a_by
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:  $1 + 50 x^{2} + 4489 x^{4}$
Frobenius angles:  $\pm0.310858471633$, $\pm0.689141528367$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{21}, \sqrt{-46})\)
Galois group:  $C_2^2$
Jacobians:  $300$
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4540$ $20611600$ $90457833820$ $406328837760000$ $1822837807096416700$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $4590$ $300764$ $20164078$ $1350125108$ $90457285470$ $6060711605324$ $406067674232158$ $27206534396294948$ $1822837809641071950$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 300 curves (of which all are hyperelliptic):

  • $y^2=59 x^6+49 x^5+3 x^4+24 x^3+26 x^2+55 x+58$
  • $y^2=41 x^6+42 x^5+32 x^4+29 x^3+37 x^2+50 x+35$
  • $y^2=39 x^5+52 x^4+54 x^3+15 x^2+61 x+29$
  • $y^2=11 x^5+37 x^4+41 x^3+30 x^2+55 x+58$
  • $y^2=21 x^6+26 x^5+19 x^4+8 x^3+38 x^2+37 x+34$
  • $y^2=3 x^6+10 x^5+11 x^4+60 x^3+2 x^2+39 x+36$
  • $y^2=6 x^6+20 x^5+22 x^4+53 x^3+4 x^2+11 x+5$
  • $y^2=45 x^6+40 x^5+35 x^3+34 x^2+63 x+9$
  • $y^2=23 x^6+13 x^5+3 x^3+x^2+59 x+18$
  • $y^2=12 x^6+53 x^5+35 x^4+5 x^2+55 x+40$
  • $y^2=24 x^6+39 x^5+3 x^4+10 x^2+43 x+13$
  • $y^2=37 x^6+34 x^5+31 x^4+33 x^3+65 x^2+2 x+59$
  • $y^2=7 x^6+x^5+62 x^4+66 x^3+63 x^2+4 x+51$
  • $y^2=5 x^6+47 x^5+x^4+22 x^3+64 x^2+59 x+6$
  • $y^2=10 x^6+27 x^5+2 x^4+44 x^3+61 x^2+51 x+12$
  • $y^2=44 x^6+38 x^5+38 x^4+24 x^2+45 x+53$
  • $y^2=21 x^6+9 x^5+9 x^4+48 x^2+23 x+39$
  • $y^2=58 x^6+53 x^5+32 x^4+43 x^3+15 x^2+22 x+66$
  • $y^2=49 x^6+39 x^5+64 x^4+19 x^3+30 x^2+44 x+65$
  • $y^2=34 x^6+58 x^5+15 x^4+26 x^3+2 x^2+59 x+48$
  • and 280 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 \(\Q(\sqrt{21}, \sqrt{-46})\).
Endomorphism algebra over $\overline{\F}_{67}$
The base change of $A$ to $\F_{67^{2}}$ is 1.4489.by 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-966}) \)$)$

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_aby$4$(not in LMFDB)