Properties

Label 2.47.a_ak
Base field $\F_{47}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{47}$
Dimension:  $2$
L-polynomial:  $1 - 10 x^{2} + 2209 x^{4}$
Frobenius angles:  $\pm0.233036522973$, $\pm0.766963477027$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-21}, \sqrt{26})\)
Galois group:  $C_2^2$
Jacobians:  $300$
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is simple but not geometrically 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $2200$ $4840000$ $10779280600$ $23853456000000$ $52599132002791000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $48$ $2190$ $103824$ $4888318$ $229345008$ $10779345870$ $506623120464$ $23811268890238$ $1119130473102768$ $52599131769751950$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 300 curves (of which all are hyperelliptic):

  • $y^2=14 x^6+28 x^5+9 x^4+15 x^3+40 x^2+31 x+6$
  • $y^2=33 x^6+39 x^5+8 x^4+13 x^3+x^2+33 x+41$
  • $y^2=29 x^6+6 x^5+46 x^4+8 x^3+22 x^2+8 x+44$
  • $y^2=4 x^6+30 x^5+42 x^4+40 x^3+16 x^2+40 x+32$
  • $y^2=4 x^6+27 x^5+10 x^4+2 x^3+15 x^2+40 x+44$
  • $y^2=20 x^6+41 x^5+3 x^4+10 x^3+28 x^2+12 x+32$
  • $y^2=26 x^6+31 x^5+35 x^4+6 x^3+37 x^2+44 x+25$
  • $y^2=36 x^6+14 x^5+34 x^4+30 x^3+44 x^2+32 x+31$
  • $y^2=3 x^6+14 x^5+33 x^4+43 x^3+5 x^2+9 x+8$
  • $y^2=15 x^6+23 x^5+24 x^4+27 x^3+25 x^2+45 x+40$
  • $y^2=16 x^6+17 x^5+40 x^4+17 x^3+27 x^2+12 x+11$
  • $y^2=33 x^6+38 x^5+12 x^4+38 x^3+41 x^2+13 x+8$
  • $y^2=45 x^6+44 x^5+14 x^4+46 x^3+34 x^2+42 x+10$
  • $y^2=37 x^6+32 x^5+23 x^4+42 x^3+29 x^2+22 x+3$
  • $y^2=32 x^6+31 x^5+43 x^4+21 x^3+7 x^2+34 x+4$
  • $y^2=13 x^6+17 x^5+9 x^4+24 x^3+34 x^2+x+37$
  • $y^2=18 x^6+38 x^5+45 x^4+26 x^3+29 x^2+5 x+44$
  • $y^2=3 x^6+20 x^5+46 x^4+26 x^3+19 x+32$
  • $y^2=39 x^6+21 x^5+13 x^4+15 x^3+14 x^2+13 x+28$
  • $y^2=7 x^6+11 x^5+18 x^4+28 x^3+23 x^2+18 x+46$
  • and 280 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{47^{2}}$.

Endomorphism algebra over $\F_{47}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-21}, \sqrt{26})\).
Endomorphism algebra over $\overline{\F}_{47}$
The base change of $A$ to $\F_{47^{2}}$ is 1.2209.ak 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-546}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.47.a_k$4$(not in LMFDB)