Properties

Label 2.79.a_adl
Base field $\F_{79}$
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:  $\F_{79}$
Dimension:  $2$
L-polynomial:  $1 - 89 x^{2} + 6241 x^{4}$
Frobenius angles:  $\pm0.154767475208$, $\pm0.845232524792$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-69}, \sqrt{247})\)
Galois group:  $C_2^2$
Jacobians:  $84$
Isomorphism classes:  192
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6153$ $37859409$ $243088416900$ $1517464211257449$ $9468276081708559353$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $80$ $6064$ $493040$ $38959204$ $3077056400$ $243089378278$ $19203908986160$ $1517108924101444$ $119851595982618320$ $9468276080790271504$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 84 curves (of which all are hyperelliptic):

  • $y^2=35 x^6+7 x^5+54 x^4+14 x^3+57 x^2+64 x+76$
  • $y^2=26 x^6+21 x^5+4 x^4+42 x^3+13 x^2+34 x+70$
  • $y^2=5 x^6+31 x^5+20 x^4+36 x^3+28 x^2+65 x+49$
  • $y^2=15 x^6+14 x^5+60 x^4+29 x^3+5 x^2+37 x+68$
  • $y^2=53 x^6+38 x^5+67 x^4+43 x^3+51 x^2+25 x+37$
  • $y^2=x^6+35 x^5+43 x^4+50 x^3+74 x^2+75 x+32$
  • $y^2=29 x^6+23 x^5+49 x^4+62 x^3+75 x^2+19 x+61$
  • $y^2=8 x^6+69 x^5+68 x^4+28 x^3+67 x^2+57 x+25$
  • $y^2=7 x^6+71 x^5+32 x^4+48 x^3+13 x^2+24 x+16$
  • $y^2=21 x^6+55 x^5+17 x^4+65 x^3+39 x^2+72 x+48$
  • $y^2=25 x^6+x^5+72 x^4+41 x^3+77 x^2+31 x+64$
  • $y^2=75 x^6+3 x^5+58 x^4+44 x^3+73 x^2+14 x+34$
  • $y^2=68 x^6+25 x^5+74 x^4+39 x^3+76 x^2+30 x+44$
  • $y^2=46 x^6+75 x^5+64 x^4+38 x^3+70 x^2+11 x+53$
  • $y^2=70 x^6+45 x^5+58 x^4+32 x^3+52 x^2+56 x+10$
  • $y^2=52 x^6+56 x^5+16 x^4+17 x^3+77 x^2+10 x+30$
  • $y^2=49 x^6+60 x^5+24 x^4+18 x^3+35 x^2+32 x+46$
  • $y^2=32 x^6+19 x^5+27 x^4+18 x^3+49 x^2+44 x+22$
  • $y^2=10 x^6+42 x^5+15 x^4+65 x^3+65 x^2+5 x+10$
  • $y^2=30 x^6+47 x^5+45 x^4+37 x^3+37 x^2+15 x+30$
  • and 64 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{79^{2}}$.

Endomorphism algebra over $\F_{79}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-69}, \sqrt{247})\).
Endomorphism algebra over $\overline{\F}_{79}$
The base change of $A$ to $\F_{79^{2}}$ is 1.6241.adl 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-17043}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.79.a_dl$4$(not in LMFDB)