Properties

Label 2.67.a_dl
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:  $1 + 89 x^{2} + 4489 x^{4}$
Frobenius angles:  $\pm0.365609386970$, $\pm0.634390613030$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{5}, \sqrt{-223})\)
Galois group:  $C_2^2$
Jacobians:  $195$
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4579$ $20967241$ $90457888576$ $406110318448041$ $1822837803280040539$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $4668$ $300764$ $20153236$ $1350125108$ $90457394982$ $6060711605324$ $406067755926628$ $27206534396294948$ $1822837802008319628$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 195 curves (of which all are hyperelliptic):

  • $y^2=64 x^6+66 x^5+66 x^4+31 x^3+15 x^2+46 x+35$
  • $y^2=61 x^6+65 x^5+65 x^4+62 x^3+30 x^2+25 x+3$
  • $y^2=37 x^6+47 x^5+40 x^4+62 x^3+40 x^2+13 x+38$
  • $y^2=7 x^6+27 x^5+13 x^4+57 x^3+13 x^2+26 x+9$
  • $y^2=23 x^6+47 x^5+58 x^4+3 x^3+65 x^2+2 x+50$
  • $y^2=46 x^6+27 x^5+49 x^4+6 x^3+63 x^2+4 x+33$
  • $y^2=24 x^6+39 x^5+49 x^4+4 x^3+47 x^2+19 x+24$
  • $y^2=48 x^6+11 x^5+31 x^4+8 x^3+27 x^2+38 x+48$
  • $y^2=16 x^6+36 x^5+9 x^4+24 x^3+54 x^2+11 x+8$
  • $y^2=32 x^6+5 x^5+18 x^4+48 x^3+41 x^2+22 x+16$
  • $y^2=43 x^6+9 x^5+50 x^4+23 x^3+4 x^2+27 x+39$
  • $y^2=19 x^6+18 x^5+33 x^4+46 x^3+8 x^2+54 x+11$
  • $y^2=5 x^6+3 x^5+57 x^4+13 x^3+56 x^2+11 x+9$
  • $y^2=19 x^6+25 x^5+49 x^4+57 x^3+28 x^2+43 x+58$
  • $y^2=38 x^6+50 x^5+31 x^4+47 x^3+56 x^2+19 x+49$
  • $y^2=5 x^6+35 x^5+40 x^4+58 x^3+56 x^2+44 x+37$
  • $y^2=10 x^6+3 x^5+13 x^4+49 x^3+45 x^2+21 x+7$
  • $y^2=26 x^6+16 x^5+14 x^4+14 x^3+46 x^2+36 x+63$
  • $y^2=64 x^6+56 x^5+16 x^4+7 x^3+37 x^2+11 x+36$
  • $y^2=61 x^6+45 x^5+32 x^4+14 x^3+7 x^2+22 x+5$
  • and 175 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 \(\Q(\sqrt{5}, \sqrt{-223})\).
Endomorphism algebra over $\overline{\F}_{67}$
The base change of $A$ to $\F_{67^{2}}$ is 1.4489.dl 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1115}) \)$)$

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_adl$4$(not in LMFDB)