Properties

Label 2.41.ai_ck
Base field $\F_{41}$
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:  $\F_{41}$
Dimension:  $2$
L-polynomial:  $( 1 - 10 x + 41 x^{2} )( 1 + 2 x + 41 x^{2} )$
  $1 - 8 x + 62 x^{2} - 328 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.214776712523$, $\pm0.549915982954$
Angle rank:  $2$ (numerical)
Jacobians:  $224$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1408$ $2928640$ $4749635968$ $7985815552000$ $13426848293761408$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $34$ $1742$ $68914$ $2826078$ $115892354$ $4750270382$ $194753478674$ $7984919893438$ $327381934733794$ $13422659103573902$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 224 curves (of which all are hyperelliptic):

  • $y^2=36 x^6+6 x^5+28 x^4+31 x^3+40 x^2+25 x+19$
  • $y^2=21 x^6+20 x^5+8 x^4+18 x^3+18 x^2+2 x+24$
  • $y^2=5 x^6+21 x^5+12 x^4+15 x^3+30 x^2+14 x+11$
  • $y^2=27 x^6+26 x^5+12 x^4+7 x^3+28 x^2+36 x+14$
  • $y^2=14 x^6+36 x^5+27 x^4+39 x^3+8 x^2+35 x+27$
  • $y^2=31 x^6+28 x^5+38 x^4+17 x^3+11 x^2+5 x+40$
  • $y^2=13 x^6+15 x^5+4 x^4+16 x^3+22 x^2+13 x+28$
  • $y^2=3 x^6+12 x^5+25 x^4+26 x^3+x+13$
  • $y^2=17 x^6+27 x^5+12 x^4+25 x^3+22 x^2+15 x+1$
  • $y^2=x^6+14 x^5+15 x^4+10 x^3+20 x^2+18 x+20$
  • $y^2=29 x^6+24 x^5+16 x^4+11 x^3+33 x^2+x+10$
  • $y^2=18 x^6+22 x^5+x^3+37 x^2+34 x+24$
  • $y^2=38 x^6+8 x^5+8 x^4+8 x^3+28 x^2+6 x+11$
  • $y^2=28 x^6+4 x^5+8 x^4+11 x^3+8 x^2+4 x+28$
  • $y^2=12 x^6+9 x^5+17 x^4+14 x^3+7 x^2+17 x+10$
  • $y^2=5 x^6+2 x^5+23 x^4+4 x^3+4 x^2+17 x+33$
  • $y^2=26 x^6+34 x^5+x^4+26 x^3+3 x^2+39 x+34$
  • $y^2=8 x^6+32 x^5+16 x^4+7 x^3+12 x^2+32 x+30$
  • $y^2=22 x^6+23 x^5+14 x^4+7 x^3+31 x^2+34 x+11$
  • $y^2=30 x^6+14 x^5+34 x^4+37 x^3+28 x^2+19 x+7$
  • and 204 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41}$.

Endomorphism algebra over $\F_{41}$
The isogeny class factors as 1.41.ak $\times$ 1.41.c 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 are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.41.am_dy$2$(not in LMFDB)
2.41.i_ck$2$(not in LMFDB)
2.41.m_dy$2$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.am_dy$2$(not in LMFDB)
2.41.i_ck$2$(not in LMFDB)
2.41.m_dy$2$(not in LMFDB)
2.41.ak_du$4$(not in LMFDB)
2.41.ag_co$4$(not in LMFDB)
2.41.g_co$4$(not in LMFDB)
2.41.k_du$4$(not in LMFDB)