Properties

Label 2.17.a_aba
Base field $\F_{17}$
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:  $\F_{17}$
Dimension:  $2$
L-polynomial:  $1 - 26 x^{2} + 289 x^{4}$
Frobenius angles:  $\pm0.111442130273$, $\pm0.888557869727$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-2}, \sqrt{15})\)
Galois group:  $C_2^2$
Jacobians:  $8$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $264$ $69696$ $24142536$ $6959563776$ $2015996558664$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $18$ $238$ $4914$ $83326$ $1419858$ $24147502$ $410338674$ $6976072318$ $118587876498$ $2015999216878$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 8 curves (of which all are hyperelliptic):

  • $y^2=4 x^6+10 x^5+6 x^3+x^2+x+11$
  • $y^2=16 x^6+16 x^5+14 x^3+3 x^2+1$
  • $y^2=14 x^6+9 x^4+6 x^3+10 x^2+11 x+4$
  • $y^2=x^6+16 x^5+13 x^4+4 x^3+7 x^2+3 x+13$
  • $y^2=13 x^6+2 x^5+2 x^4+3 x^3+3 x^2+9 x+10$
  • $y^2=11 x^6+x^5+6 x^4+8 x^2+4 x+2$
  • $y^2=5 x^6+6 x^5+2 x^4+3 x^3+10 x^2+14 x+13$
  • $y^2=14 x^6+6 x^5+2 x^4+15 x^3+11 x^2+3 x+13$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{17^{2}}$.

Endomorphism algebra over $\F_{17}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-2}, \sqrt{15})\).
Endomorphism algebra over $\overline{\F}_{17}$
The base change of $A$ to $\F_{17^{2}}$ is 1.289.aba 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-30}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.17.a_ba$4$(not in LMFDB)
2.17.ae_i$8$(not in LMFDB)
2.17.e_i$8$(not in LMFDB)