Properties

Label 2.47.a_cn
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:  $1 + 65 x^{2} + 2209 x^{4}$
Frobenius angles:  $\pm0.371522557458$, $\pm0.628477442542$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{29}, \sqrt{-159})\)
Galois group:  $C_2^2$
Jacobians:  $266$
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $2275$ $5175625$ $10779059200$ $23813180015625$ $52599131948783875$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $48$ $2340$ $103824$ $4880068$ $229345008$ $10778903070$ $506623120464$ $23811306105988$ $1119130473102768$ $52599131661737700$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 266 curves (of which all are hyperelliptic):

  • $y^2=14 x^6+6 x^5+12 x^4+14 x^3+42 x^2+9 x+9$
  • $y^2=23 x^6+30 x^5+13 x^4+23 x^3+22 x^2+45 x+45$
  • $y^2=8 x^6+7 x^5+15 x^4+3 x^3+18 x^2+27 x+33$
  • $y^2=22 x^6+25 x^5+22 x^4+14 x^3+6 x^2+23 x+41$
  • $y^2=16 x^6+31 x^5+16 x^4+23 x^3+30 x^2+21 x+17$
  • $y^2=17 x^6+21 x^5+30 x^4+21 x^3+3 x^2+10 x+37$
  • $y^2=38 x^6+11 x^5+9 x^4+11 x^3+15 x^2+3 x+44$
  • $y^2=29 x^6+31 x^5+29 x^4+37 x^3+43 x^2+42 x+31$
  • $y^2=4 x^6+14 x^5+4 x^4+44 x^3+27 x^2+22 x+14$
  • $y^2=6 x^6+13 x^5+27 x^4+6 x^3+16 x^2+13 x+8$
  • $y^2=30 x^6+18 x^5+41 x^4+30 x^3+33 x^2+18 x+40$
  • $y^2=35 x^6+5 x^5+27 x^4+40 x^3+12 x^2+23 x+37$
  • $y^2=34 x^6+25 x^5+41 x^4+12 x^3+13 x^2+21 x+44$
  • $y^2=33 x^6+40 x^5+38 x^4+22 x^3+45 x^2+33 x+22$
  • $y^2=24 x^6+12 x^5+2 x^4+16 x^3+37 x^2+24 x+16$
  • $y^2=6 x^6+34 x^5+9 x^4+30 x^3+15 x^2+18 x+23$
  • $y^2=30 x^6+29 x^5+45 x^4+9 x^3+28 x^2+43 x+21$
  • $y^2=31 x^6+11 x^5+33 x^4+3 x^3+28 x^2+35 x+23$
  • $y^2=14 x^6+8 x^5+24 x^4+15 x^3+46 x^2+34 x+21$
  • $y^2=3 x^6+34 x^5+44 x^4+31 x^3+23 x^2+13 x+10$
  • and 246 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 \(\Q(\sqrt{29}, \sqrt{-159})\).
Endomorphism algebra over $\overline{\F}_{47}$
The base change of $A$ to $\F_{47^{2}}$ is 1.2209.cn 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-4611}) \)$)$

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_acn$4$(not in LMFDB)