Properties

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

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Invariants

Base field:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 - 12 x + 71 x^{2} )^{2}$
  $1 - 24 x + 286 x^{2} - 1704 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.247758306964$, $\pm0.247758306964$
Angle rank:  $1$ (numerical)
Jacobians:  $56$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3, 5$

This isogeny class is not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $3600$ $25401600$ $128694387600$ $646265881497600$ $3255467816972250000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $48$ $5038$ $359568$ $25431838$ $1804353648$ $128100344398$ $9095112059088$ $645753429760318$ $45848500075674288$ $3255243550502050798$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 56 curves (of which all are hyperelliptic):

  • $y^2=56 x^6+60 x^5+57 x^4+10 x^3+10 x^2+48 x+39$
  • $y^2=64 x^6+42 x^5+58 x^4+67 x^3+11 x^2+34 x+69$
  • $y^2=27 x^6+38 x^5+6 x^4+32 x^3+8 x^2+36 x+64$
  • $y^2=29 x^6+44 x^5+26 x^4+57 x^3+26 x^2+44 x+29$
  • $y^2=9 x^6+6 x^5+6 x^4+19 x^3+48 x^2+30 x+13$
  • $y^2=63 x^6+58 x^5+50 x^4+36 x^3+x^2+37 x+14$
  • $y^2=62 x^6+30 x^4+30 x^2+62$
  • $y^2=52 x^6+63 x^5+65 x^4+33 x^3+12 x^2+18 x+47$
  • $y^2=20 x^6+24 x^5+48 x^4+37 x^3+27 x^2+32 x+15$
  • $y^2=46 x^6+39 x^4+39 x^2+46$
  • $y^2=22 x^6+48 x^5+51 x^4+44 x^3+26 x^2+30 x+62$
  • $y^2=38 x^6+28 x^5+17 x^4+44 x^3+63 x^2+46 x+10$
  • $y^2=42 x^6+29 x^5+13 x^4+59 x^3+13 x^2+29 x+42$
  • $y^2=28 x^6+15 x^5+5 x^4+45 x^3+13 x^2+25 x+52$
  • $y^2=49 x^6+53 x^5+68 x^4+22 x^3+59 x^2+67 x+12$
  • $y^2=37 x^6+31 x^5+46 x^4+40 x^3+63 x^2+51 x+40$
  • $y^2=39 x^6+53 x^5+12 x^4+57 x^3+12 x^2+53 x+39$
  • $y^2=61 x^6+56 x^5+6 x^4+20 x^3+6 x^2+56 x+61$
  • $y^2=28 x^6+7 x^5+34 x^4+65 x^3+28 x^2+33 x+21$
  • $y^2=8 x^6+70 x^5+18 x^4+55 x^3+x^2+55 x+15$
  • and 36 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.am 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-35}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.71.a_ac$2$(not in LMFDB)
2.71.y_la$2$(not in LMFDB)
2.71.m_cv$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.71.a_ac$2$(not in LMFDB)
2.71.y_la$2$(not in LMFDB)
2.71.m_cv$3$(not in LMFDB)
2.71.a_c$4$(not in LMFDB)
2.71.am_cv$6$(not in LMFDB)