Properties

Label 2.79.a_gc
Base field $\F_{79}$
Dimension $2$
$p$-rank $0$
Ordinary no
Supersingular yes
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:  $( 1 + 79 x^{2} )^{2}$
  $1 + 158 x^{2} + 6241 x^{4}$
Frobenius angles:  $\pm0.5$, $\pm0.5$
Angle rank:  $0$ (numerical)
Jacobians:  $149$
Cyclic group of points:    no
Non-cyclic primes:   $2, 5$

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

Newton polygon

This isogeny class is supersingular.

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

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6400$ $40960000$ $243088441600$ $1516136693760000$ $9468276088780960000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $80$ $6558$ $493040$ $38925118$ $3077056400$ $243089427678$ $19203908986160$ $1517108654106238$ $119851595982618320$ $9468276094935072798$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 149 curves (of which all are hyperelliptic):

  • $y^2=x^5+78$
  • $y^2=3 x^5+76$
  • $y^2=16 x^6+x^5+16 x^4+9 x^3+62 x^2+53 x+10$
  • $y^2=48 x^6+3 x^5+48 x^4+27 x^3+28 x^2+x+30$
  • $y^2=67 x^6+50 x^5+23 x^4+78 x^3+37 x^2+3 x+33$
  • $y^2=43 x^6+71 x^5+69 x^4+76 x^3+32 x^2+9 x+20$
  • $y^2=66 x^6+72 x^5+7 x^4+22 x^3+48 x^2+50 x+60$
  • $y^2=40 x^6+58 x^5+21 x^4+66 x^3+65 x^2+71 x+22$
  • $y^2=76 x^6+60 x^5+44 x^4+73 x^3+74 x^2+55 x+34$
  • $y^2=70 x^6+22 x^5+53 x^4+61 x^3+64 x^2+7 x+23$
  • $y^2=58 x^6+11 x^5+21 x^3+9 x+57$
  • $y^2=16 x^6+33 x^5+63 x^3+27 x+13$
  • $y^2=40 x^6+47 x^5+39 x^4+7 x^3+39 x^2+47 x+40$
  • $y^2=41 x^6+62 x^5+38 x^4+21 x^3+38 x^2+62 x+41$
  • $y^2=29 x^6+39 x^5+31 x^4+7 x^3+12 x^2+32 x+37$
  • $y^2=8 x^6+38 x^5+14 x^4+21 x^3+36 x^2+17 x+32$
  • $y^2=12 x^6+28 x^5+5 x^4+29 x^3+2 x^2+74 x+33$
  • $y^2=36 x^6+5 x^5+15 x^4+8 x^3+6 x^2+64 x+20$
  • $y^2=59 x^6+23 x^5+70 x^4+13 x^3+70 x^2+23 x+59$
  • $y^2=19 x^6+69 x^5+52 x^4+39 x^3+52 x^2+69 x+19$
  • and 129 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 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-79}) \)$)$
Endomorphism algebra over $\overline{\F}_{79}$
The base change of $A$ to $\F_{79^{2}}$ is 1.6241.gc 2 and its endomorphism algebra is $\mathrm{M}_{2}(B)$, where $B$ is the quaternion algebra over \(\Q\) ramified at $79$ and $\infty$.

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.79.a_adb$3$(not in LMFDB)
2.79.a_agc$4$(not in LMFDB)
2.79.a_a$8$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.79.a_adb$3$(not in LMFDB)
2.79.a_agc$4$(not in LMFDB)
2.79.a_a$8$(not in LMFDB)
2.79.a_db$12$(not in LMFDB)