Properties

Label 2.71.ak_cc
Base field $\F_{71}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $1 - 10 x + 54 x^{2} - 710 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.121971596996$, $\pm0.608428168607$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-146 +10 \sqrt{113}})\)
Galois group:  $D_{4}$
Jacobians:  $180$
Isomorphism classes:  288
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4376$ $25450816$ $127561052024$ $645690866837504$ $3255447344743896376$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $62$ $5050$ $356402$ $25409214$ $1804342302$ $128100434266$ $9095121422162$ $645753628400574$ $45848501159116862$ $3255243550309592250$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 180 curves (of which all are hyperelliptic):

  • $y^2=6 x^6+19 x^5+31 x^4+56 x^3+13 x^2+4 x+4$
  • $y^2=63 x^6+43 x^5+40 x^4+23 x^3+26 x^2+20 x+70$
  • $y^2=20 x^6+41 x^5+50 x^4+10 x^3+64 x^2+62 x+5$
  • $y^2=29 x^6+37 x^5+47 x^4+51 x^3+5 x^2+46 x+24$
  • $y^2=21 x^6+4 x^5+38 x^4+51 x^3+38 x^2+59 x+36$
  • $y^2=8 x^6+5 x^5+4 x^4+4 x^3+53 x^2+17 x+51$
  • $y^2=43 x^6+19 x^5+36 x^4+19 x^3+41 x^2+44 x+14$
  • $y^2=22 x^6+15 x^5+22 x^4+32 x^3+26 x^2+8 x+50$
  • $y^2=62 x^6+27 x^5+63 x^4+23 x^3+57 x^2+13 x+70$
  • $y^2=13 x^6+51 x^5+42 x^4+44 x^3+4 x^2+70 x+60$
  • $y^2=56 x^6+28 x^5+10 x^4+48 x^3+13 x^2+3 x+12$
  • $y^2=22 x^6+25 x^5+29 x^4+50 x^3+2 x+59$
  • $y^2=59 x^6+49 x^5+39 x^4+34 x^3+29 x^2+47 x+7$
  • $y^2=16 x^6+24 x^5+24 x^4+63 x^3+5 x^2+56 x+24$
  • $y^2=58 x^6+59 x^5+46 x^4+19 x^3+51 x^2+7 x+40$
  • $y^2=28 x^6+45 x^5+49 x^4+12 x^3+67 x^2+28 x+2$
  • $y^2=66 x^6+64 x^5+51 x^4+17 x^3+34 x^2+2 x+26$
  • $y^2=49 x^6+16 x^5+38 x^3+66 x^2+67 x+42$
  • $y^2=46 x^6+51 x^5+52 x^4+67 x^3+26 x^2+3 x+65$
  • $y^2=51 x^6+30 x^5+52 x^4+30 x^3+11 x^2+52 x+51$
  • and 160 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71}$.

Endomorphism algebra over $\F_{71}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-146 +10 \sqrt{113}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.71.k_cc$2$(not in LMFDB)