Properties

Label 2.79.a_ei
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:  $1 + 112 x^{2} + 6241 x^{4}$
Frobenius angles:  $\pm0.375395275078$, $\pm0.624604724922$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-30}, \sqrt{46})\)
Galois group:  $C_2^2$
Jacobians:  $240$
Cyclic group of points:    no
Non-cyclic primes:   $3$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6354$ $40373316$ $243086763474$ $1517104058000400$ $9468276078221531154$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $80$ $6466$ $493040$ $38949958$ $3077056400$ $243086071426$ $19203908986160$ $1517108965699198$ $119851595982618320$ $9468276073816215106$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 240 curves (of which all are hyperelliptic):

  • $y^2=44 x^6+40 x^5+11 x^4+x^3+20 x^2+2 x+6$
  • $y^2=53 x^6+41 x^5+33 x^4+3 x^3+60 x^2+6 x+18$
  • $y^2=60 x^6+38 x^5+3 x^4+x^3+46 x+40$
  • $y^2=22 x^6+35 x^5+9 x^4+3 x^3+59 x+41$
  • $y^2=73 x^6+31 x^5+49 x^4+69 x^3+13 x^2+65 x+49$
  • $y^2=61 x^6+14 x^5+68 x^4+49 x^3+39 x^2+37 x+68$
  • $y^2=16 x^6+24 x^5+54 x^4+72 x^3+14 x^2+74 x+16$
  • $y^2=48 x^6+72 x^5+4 x^4+58 x^3+42 x^2+64 x+48$
  • $y^2=38 x^6+46 x^5+51 x^4+31 x^3+11 x^2+67 x+72$
  • $y^2=35 x^6+59 x^5+74 x^4+14 x^3+33 x^2+43 x+58$
  • $y^2=45 x^6+71 x^5+7 x^4+x^3+62 x^2+53 x+55$
  • $y^2=56 x^6+55 x^5+21 x^4+3 x^3+28 x^2+x+7$
  • $y^2=7 x^6+13 x^5+66 x^4+40 x^3+14 x^2+36 x+76$
  • $y^2=21 x^6+39 x^5+40 x^4+41 x^3+42 x^2+29 x+70$
  • $y^2=68 x^6+74 x^5+40 x^4+37 x^3+50 x^2+28 x+51$
  • $y^2=46 x^6+64 x^5+41 x^4+32 x^3+71 x^2+5 x+74$
  • $y^2=59 x^6+44 x^5+8 x^4+12 x^3+61 x^2+69 x+3$
  • $y^2=19 x^6+53 x^5+24 x^4+36 x^3+25 x^2+49 x+9$
  • $y^2=17 x^6+17 x^5+45 x^4+75 x^3+59 x^2+17 x+53$
  • $y^2=51 x^6+51 x^5+56 x^4+67 x^3+19 x^2+51 x+1$
  • and 220 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 \(\Q(\sqrt{-30}, \sqrt{46})\).
Endomorphism algebra over $\overline{\F}_{79}$
The base change of $A$ to $\F_{79^{2}}$ is 1.6241.ei 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-345}) \)$)$

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_aei$4$(not in LMFDB)