Properties

Label 2.79.k_gc
Base field $\F_{79}$
Dimension $2$
$p$-rank $1$
Ordinary no
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{79}$
Dimension:  $2$
L-polynomial:  $( 1 + 79 x^{2} )( 1 + 10 x + 79 x^{2} )$
  $1 + 10 x + 158 x^{2} + 790 x^{3} + 6241 x^{4}$
Frobenius angles:  $\pm0.5$, $\pm0.690177289346$
Angle rank:  $1$ (numerical)
Jacobians:  $400$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3, 5$

This isogeny class is not simple, primitive, not ordinary, and not supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

$p$-rank:  $1$
Slopes:  $[0, 1/2, 1/2, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7200$ $40320000$ $242412976800$ $1516977745920000$ $9468328552592580000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $90$ $6458$ $491670$ $38946718$ $3077073450$ $243087550778$ $19203916547430$ $1517108726768638$ $119851595437655610$ $9468276094644370298$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 400 curves (of which all are hyperelliptic):

  • $y^2=x^6+15 x^5+70 x^4+70 x^3+10 x^2+78 x+47$
  • $y^2=51 x^6+52 x^5+45 x^4+18 x^3+68 x^2+46 x$
  • $y^2=77 x^6+59 x^5+15 x^4+28 x^3+18 x^2+21 x+50$
  • $y^2=37 x^6+71 x^5+7 x^4+28 x^3+27 x^2+14 x+31$
  • $y^2=44 x^6+15 x^5+30 x^4+38 x^3+6 x^2+48 x+25$
  • $y^2=24 x^6+12 x^5+69 x^4+75 x^3+69 x^2+12 x+24$
  • $y^2=76 x^6+36 x^5+53 x^4+21 x^3+63 x^2+45 x+22$
  • $y^2=16 x^6+15 x^5+24 x^4+53 x^3+67 x^2+18 x+50$
  • $y^2=7 x^6+39 x^5+22 x^4+50 x^3+16 x^2+30 x+15$
  • $y^2=30 x^6+78 x^5+65 x^4+59 x^3+6 x^2+49 x+27$
  • $y^2=18 x^6+20 x^5+48 x^4+63 x^3+37 x^2+40 x+8$
  • $y^2=16 x^6+33 x^5+49 x^4+55 x^3+49 x^2+33 x+16$
  • $y^2=52 x^6+56 x^5+51 x^4+12 x^3+x^2+5 x+63$
  • $y^2=76 x^6+65 x^5+60 x^4+72 x^3+67 x^2+25 x+75$
  • $y^2=68 x^6+67 x^5+60 x^4+74 x^3+5 x^2+55 x+21$
  • $y^2=24 x^6+51 x^5+47 x^4+75 x^3+16 x^2+69 x+34$
  • $y^2=78 x^6+x^5+48 x^4+27 x^3+47 x^2+71 x+37$
  • $y^2=56 x^6+61 x^5+16 x^4+21 x^3+13 x^2+6 x+59$
  • $y^2=52 x^6+16 x^5+19 x^4+78 x^3+73 x^2+37 x+24$
  • $y^2=44 x^6+33 x^5+19 x^4+29 x^3+52 x^2+5 x+69$
  • and 380 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{79}$
The isogeny class factors as 1.79.a $\times$ 1.79.k and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:
Endomorphism algebra over $\overline{\F}_{79}$
The base change of $A$ to $\F_{79^{2}}$ is 1.6241.cg $\times$ 1.6241.gc. The endomorphism algebra for each factor is:

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_gc$2$(not in LMFDB)