Properties

Label 2.79.k_fa
Base field $\F_{79}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{79}$
Dimension:  $2$
L-polynomial:  $1 + 10 x + 130 x^{2} + 790 x^{3} + 6241 x^{4}$
Frobenius angles:  $\pm0.459058809679$, $\pm0.742745965286$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-238 +10 \sqrt{53}})\)
Galois group:  $D_{4}$
Jacobians:  $264$
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is simple and 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7172$ $39962384$ $242826570932$ $1517169670666496$ $9467858998377840852$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $90$ $6402$ $492510$ $38951646$ $3076920850$ $243088027842$ $19203922956630$ $1517108693123838$ $119851595728119210$ $9468276085745072002$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 264 curves (of which all are hyperelliptic):

  • $y^2=60 x^6+38 x^5+21 x^4+34 x^3+18 x^2+75 x+1$
  • $y^2=10 x^6+55 x^5+33 x^4+60 x^3+14 x^2+19 x+71$
  • $y^2=76 x^6+36 x^5+44 x^4+70 x^3+6 x^2+50 x+52$
  • $y^2=50 x^6+40 x^5+46 x^4+60 x^3+35 x+17$
  • $y^2=7 x^6+72 x^5+61 x^4+65 x^3+28 x^2+17 x+29$
  • $y^2=18 x^6+45 x^5+72 x^4+77 x^3+4 x^2+41 x+9$
  • $y^2=46 x^6+22 x^5+14 x^4+15 x^3+13 x^2+56 x+75$
  • $y^2=18 x^6+63 x^5+58 x^4+26 x^3+2 x^2+65 x+3$
  • $y^2=13 x^6+73 x^5+10 x^4+16 x^3+7 x^2+75 x+51$
  • $y^2=55 x^6+38 x^5+3 x^4+49 x^3+44 x^2+28 x+12$
  • $y^2=57 x^6+50 x^5+57 x^4+6 x^3+38 x^2+37 x+4$
  • $y^2=73 x^6+52 x^5+28 x^4+54 x^3+12 x^2+46 x+2$
  • $y^2=65 x^6+51 x^5+51 x^4+22 x^3+11 x^2+x+25$
  • $y^2=3 x^6+69 x^5+74 x^4+37 x^3+3 x^2+27 x+78$
  • $y^2=37 x^6+76 x^5+56 x^4+54 x^3+43 x^2+77 x+21$
  • $y^2=40 x^6+72 x^5+49 x^4+51 x^3+77 x^2+9 x+70$
  • $y^2=39 x^6+69 x^5+37 x^4+65 x^3+9 x^2+13 x+34$
  • $y^2=45 x^6+20 x^5+11 x^4+9 x^3+20 x^2+33 x+29$
  • $y^2=33 x^6+x^5+55 x^4+47 x^3+49 x^2+32 x+43$
  • $y^2=20 x^6+65 x^5+4 x^4+17 x^3+71 x^2+x+25$
  • and 244 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{79}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-238 +10 \sqrt{53}})\).

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.ak_fa$2$(not in LMFDB)