Properties

Label 2.41.ad_bc
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:  $( 1 - 9 x + 41 x^{2} )( 1 + 6 x + 41 x^{2} )$
  $1 - 3 x + 28 x^{2} - 123 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.251940962052$, $\pm0.655213070720$
Angle rank:  $2$ (numerical)
Jacobians:  $210$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1584$ $2908224$ $4740120000$ $7997953353984$ $13425982155591984$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $39$ $1729$ $68778$ $2830369$ $115884879$ $4749964558$ $194753860599$ $7984923683329$ $327381875941338$ $13422659362051729$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 210 curves (of which all are hyperelliptic):

  • $y^2=30 x^6+2 x^5+35 x^4+3 x^3+9 x^2+19 x+27$
  • $y^2=12 x^6+22 x^5+28 x^4+28 x^3+16 x^2+x+3$
  • $y^2=21 x^6+29 x^5+6 x^4+2 x^3+27 x^2+36 x+7$
  • $y^2=31 x^6+7 x^5+8 x^4+26 x^3+14 x^2+15 x+26$
  • $y^2=27 x^6+11 x^5+34 x^3+14 x^2+37 x$
  • $y^2=x^6+16 x^5+26 x^4+34 x^3+34 x^2+34 x+12$
  • $y^2=29 x^5+9 x^4+38 x^3+7 x^2+29 x+11$
  • $y^2=33 x^6+x^5+35 x^4+15 x^3+38 x^2+14 x+24$
  • $y^2=11 x^6+33 x^5+19 x^4+14 x^3+26 x^2+32 x+19$
  • $y^2=30 x^6+11 x^4+6 x^2+31 x+33$
  • $y^2=10 x^6+3 x^5+37 x^4+19 x^3+27 x^2+31$
  • $y^2=28 x^6+3 x^5+35 x^4+13 x^3+36 x^2+21 x+12$
  • $y^2=5 x^6+6 x^5+9 x^4+26 x^3+4 x^2+2 x+24$
  • $y^2=38 x^6+28 x^5+8 x^4+4 x^3+23 x+39$
  • $y^2=20 x^6+5 x^5+24 x^4+2 x^3+39 x^2+25 x+19$
  • $y^2=6 x^6+12 x^5+13 x^4+39 x^3+4 x^2+9 x+38$
  • $y^2=39 x^6+20 x^5+40 x^4+8 x^3+6 x^2+7 x+24$
  • $y^2=24 x^6+7 x^5+15 x^4+20 x^3+19 x^2+7 x+15$
  • $y^2=x^6+18 x^5+30 x^4+21 x^3+9 x^2+40 x+4$
  • $y^2=25 x^6+23 x^5+34 x^4+38 x^3+28 x^2+12 x+11$
  • and 190 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.aj $\times$ 1.41.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
2.41.ap_fg$2$(not in LMFDB)
2.41.d_bc$2$(not in LMFDB)
2.41.p_fg$2$(not in LMFDB)