Properties

Label 2.67.a_k
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:  $1 + 10 x^{2} + 4489 x^{4}$
Frobenius angles:  $\pm0.261888286667$, $\pm0.738111713333$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(i, \sqrt{31})\)
Galois group:  $C_2^2$
Jacobians:  $759$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4500$ $20250000$ $90458248500$ $406425600000000$ $1822837805536972500$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $4510$ $300764$ $20168878$ $1350125108$ $90458114830$ $6060711605324$ $406067600523358$ $27206534396294948$ $1822837806522183550$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 759 curves (of which all are hyperelliptic):

  • $y^2=61 x^6+35 x^5+56 x^3+21 x+19$
  • $y^2=35 x^6+52 x^5+33 x^4+58 x^3+22 x^2+45 x+56$
  • $y^2=3 x^6+37 x^5+66 x^4+49 x^3+44 x^2+23 x+45$
  • $y^2=14 x^6+53 x^5+22 x^4+34 x^3+64 x^2+44 x+37$
  • $y^2=28 x^6+39 x^5+44 x^4+x^3+61 x^2+21 x+7$
  • $y^2=36 x^6+10 x^5+22 x^4+62 x^3+51 x^2+44 x+45$
  • $y^2=5 x^6+20 x^5+44 x^4+57 x^3+35 x^2+21 x+23$
  • $y^2=22 x^6+28 x^5+57 x^4+44 x^3+46 x^2+18 x+20$
  • $y^2=44 x^6+56 x^5+47 x^4+21 x^3+25 x^2+36 x+40$
  • $y^2=53 x^6+40 x^5+45 x^4+21 x^3+29 x^2+54 x+24$
  • $y^2=45 x^6+22 x^5+32 x^4+30 x^3+54 x^2+37 x+59$
  • $y^2=63 x^6+57 x^5+27 x^4+24 x^3+51 x^2+29 x+36$
  • $y^2=59 x^6+47 x^5+54 x^4+48 x^3+35 x^2+58 x+5$
  • $y^2=30 x^6+49 x^5+36 x^4+29 x^3+6 x^2+28 x+49$
  • $y^2=60 x^6+31 x^5+5 x^4+58 x^3+12 x^2+56 x+31$
  • $y^2=54 x^6+18 x^5+18 x^4+61 x^3+40 x^2+28 x+39$
  • $y^2=41 x^6+36 x^5+36 x^4+55 x^3+13 x^2+56 x+11$
  • $y^2=20 x^6+49 x^5+49 x^4+34 x^3+47 x^2+44 x+22$
  • $y^2=40 x^6+31 x^5+31 x^4+x^3+27 x^2+21 x+44$
  • $y^2=36 x^6+45 x^5+40 x^4+38 x^3+24 x^2+19 x+26$
  • and 739 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 \(\Q(i, \sqrt{31})\).
Endomorphism algebra over $\overline{\F}_{67}$
The base change of $A$ to $\F_{67^{2}}$ is 1.4489.k 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-31}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.67.ay_ks$4$(not in LMFDB)
2.67.a_ak$4$(not in LMFDB)
2.67.y_ks$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.67.ay_ks$4$(not in LMFDB)
2.67.a_ak$4$(not in LMFDB)
2.67.y_ks$4$(not in LMFDB)
2.67.am_cz$12$(not in LMFDB)
2.67.m_cz$12$(not in LMFDB)