Properties

Label 2.61.i_fe
Base field $\F_{61}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{61}$
Dimension:  $2$
L-polynomial:  $( 1 + 2 x + 61 x^{2} )( 1 + 6 x + 61 x^{2} )$
  $1 + 8 x + 134 x^{2} + 488 x^{3} + 3721 x^{4}$
Frobenius angles:  $\pm0.540867587811$, $\pm0.625491882155$
Angle rank:  $2$ (numerical)
Jacobians:  $112$
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4352$ $14622720$ $51239686400$ $191618228551680$ $713417516717050112$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $70$ $3926$ $225742$ $13839406$ $844684630$ $51520376198$ $3142738740190$ $191707326362206$ $11694146205191782$ $713342910965055926$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 112 curves (of which all are hyperelliptic):

  • $y^2=15 x^6+31 x^5+55 x^4+31 x^3+55 x^2+31 x+15$
  • $y^2=28 x^6+60 x^5+30 x^4+30 x^2+60 x+28$
  • $y^2=48 x^6+52 x^5+40 x^4+16 x^3+18 x^2+27 x+45$
  • $y^2=52 x^6+47 x^5+17 x^4+42 x^3+9 x^2+35 x+54$
  • $y^2=54 x^6+25 x^5+x^4+48 x^3+25 x^2+9 x+59$
  • $y^2=47 x^6+34 x^5+13 x^4+13 x^3+19 x^2+47 x+49$
  • $y^2=15 x^6+10 x^5+59 x^4+5 x^3+59 x^2+10 x+15$
  • $y^2=13 x^6+30 x^5+14 x^4+18 x^3+28 x^2+30 x+10$
  • $y^2=13 x^6+38 x^5+49 x^4+14 x^3+49 x^2+38 x+13$
  • $y^2=8 x^6+26 x^5+36 x^4+32 x^3+3 x^2+40 x+37$
  • $y^2=5 x^6+10 x^5+36 x^4+58 x^3+36 x^2+10 x+5$
  • $y^2=5 x^6+4 x^5+23 x^4+14 x^3+23 x^2+4 x+5$
  • $y^2=40 x^6+34 x^5+24 x^4+9 x^3+24 x^2+34 x+40$
  • $y^2=22 x^6+41 x^5+44 x^4+53 x^3+7 x^2+46 x+56$
  • $y^2=41 x^6+2 x^5+60 x^4+55 x^3+46 x^2+23 x+27$
  • $y^2=43 x^6+58 x^5+59 x^4+20 x^3+55 x^2+34 x+2$
  • $y^2=34 x^6+36 x^5+50 x^4+29 x^3+50 x^2+36 x+34$
  • $y^2=22 x^6+26 x^5+38 x^4+17 x^3+38 x^2+26 x+22$
  • $y^2=56 x^6+34 x^5+19 x^4+49 x^3+22 x^2+15 x+5$
  • $y^2=46 x^6+28 x^5+16 x^4+11 x^3+16 x^2+28 x+46$
  • and 92 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61}$.

Endomorphism algebra over $\F_{61}$
The isogeny class factors as 1.61.c $\times$ 1.61.g and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. 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
2.61.ai_fe$2$(not in LMFDB)
2.61.ae_eg$2$(not in LMFDB)
2.61.e_eg$2$(not in LMFDB)