Properties

Label 2.41.a_as
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:  $( 1 - 10 x + 41 x^{2} )( 1 + 10 x + 41 x^{2} )$
  $1 - 18 x^{2} + 1681 x^{4}$
Frobenius angles:  $\pm0.214776712523$, $\pm0.785223287477$
Angle rank:  $1$ (numerical)
Jacobians:  $149$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1664$ $2768896$ $4750189184$ $8002109440000$ $13422659102962304$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $42$ $1646$ $68922$ $2831838$ $115856202$ $4750274126$ $194754273882$ $7984918073278$ $327381934393962$ $13422658895772206$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 149 curves (of which all are hyperelliptic):

  • $y^2=33 x^6+22 x^5+6 x^4+10 x^3+38 x^2+18 x$
  • $y^2=34 x^6+9 x^5+36 x^4+19 x^3+23 x^2+26 x$
  • $y^2=15 x^6+27 x^5+17 x^4+40 x^3+9 x^2+17 x+9$
  • $y^2=8 x^6+39 x^5+20 x^4+35 x^3+13 x^2+20 x+13$
  • $y^2=28 x^6+9 x^5+30 x^4+24 x^3+36 x^2+27 x+1$
  • $y^2=4 x^6+13 x^5+16 x^4+21 x^3+11 x^2+39 x+6$
  • $y^2=15 x^6+11 x^5+26 x^4+37 x^3+x^2+19 x+2$
  • $y^2=38 x^6+12 x^5+32 x^4+8 x^3+10 x^2+18 x+4$
  • $y^2=23 x^6+31 x^5+28 x^4+7 x^3+19 x^2+26 x+24$
  • $y^2=34 x^6+10 x^5+11 x^4+39 x^3+40 x^2+40 x+31$
  • $y^2=34 x^6+30 x^5+6 x^4+2 x^3+5 x^2+14 x+36$
  • $y^2=16 x^6+18 x^5+12 x^4+22 x^3+5 x^2+34 x+20$
  • $y^2=14 x^6+26 x^5+31 x^4+9 x^3+30 x^2+40 x+38$
  • $y^2=17 x^6+23 x^5+2 x^4+34 x^3+24 x^2+11 x+4$
  • $y^2=20 x^6+15 x^5+12 x^4+40 x^3+21 x^2+25 x+24$
  • $y^2=33 x^6+27 x^4+11 x^3+36 x^2+4 x+25$
  • $y^2=34 x^6+39 x^4+25 x^3+11 x^2+24 x+27$
  • $y^2=14 x^6+35 x^5+35 x^4+9 x^3+40 x^2+8 x+17$
  • $y^2=5 x^6+21 x^4+3 x^2+14$
  • $y^2=38 x^6+15 x^4+8 x^2+8$
  • and 129 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41^{2}}$.

Endomorphism algebra over $\F_{41}$
The isogeny class factors as 1.41.ak $\times$ 1.41.k and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:
Endomorphism algebra over $\overline{\F}_{41}$
The base change of $A$ to $\F_{41^{2}}$ is 1.1681.as 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1}) \)$)$

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.au_ha$2$(not in LMFDB)
2.41.u_ha$2$(not in LMFDB)
2.41.as_gg$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.41.au_ha$2$(not in LMFDB)
2.41.u_ha$2$(not in LMFDB)
2.41.as_gg$4$(not in LMFDB)
2.41.aq_fq$4$(not in LMFDB)
2.41.ac_c$4$(not in LMFDB)
2.41.a_s$4$(not in LMFDB)
2.41.c_c$4$(not in LMFDB)
2.41.q_fq$4$(not in LMFDB)
2.41.s_gg$4$(not in LMFDB)
2.41.ak_ch$6$(not in LMFDB)
2.41.k_ch$6$(not in LMFDB)
2.41.a_adc$8$(not in LMFDB)
2.41.a_dc$8$(not in LMFDB)
2.41.ai_x$12$(not in LMFDB)
2.41.i_x$12$(not in LMFDB)