Properties

Label 2.17.ab_q
Base field $\F_{17}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{17}$
Dimension:  $2$
L-polynomial:  $1 - x + 16 x^{2} - 17 x^{3} + 289 x^{4}$
Frobenius angles:  $\pm0.303564039335$, $\pm0.651227252100$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-15 + \sqrt{73}})\)
Galois group:  $D_{4}$
Jacobians:  $28$
Isomorphism classes:  28
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is simple and 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $288$ $93312$ $24109056$ $7029379584$ $2018153284128$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $17$ $321$ $4910$ $84161$ $1421377$ $24119838$ $410308657$ $6975852289$ $118587711182$ $2015996831841$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 28 curves (of which all are hyperelliptic):

  • $y^2=4 x^6+11 x^5+8 x^4+13 x^3+9 x^2+x+1$
  • $y^2=10 x^6+10 x^5+15 x^4+13 x^3+15 x^2+2 x+14$
  • $y^2=7 x^6+13 x^5+15 x^4+x^3+3 x^2+16 x+8$
  • $y^2=11 x^6+5 x^5+4 x^4+16 x^3+4 x+11$
  • $y^2=15 x^6+8 x^5+10 x^4+13 x^3+16 x^2+10 x+7$
  • $y^2=2 x^6+x^5+8 x^4+16 x^3+x^2+6 x$
  • $y^2=11 x^6+3 x^4+4 x^3+12 x^2+x+1$
  • $y^2=15 x^6+5 x^5+12 x^4+13 x^3+11 x^2+6 x+6$
  • $y^2=9 x^6+14 x^5+16 x^4+7 x^3+9 x^2+8 x$
  • $y^2=13 x^6+10 x^5+10 x^4+15 x^3+13 x+7$
  • $y^2=7 x^6+2 x^5+11 x^4+15 x^3+16 x+3$
  • $y^2=12 x^6+11 x^5+4 x^4+5 x^3+7 x+7$
  • $y^2=2 x^6+14 x^5+9 x^4+13 x^2+2 x+6$
  • $y^2=16 x^6+15 x^4+3 x^3+16 x^2+10 x+12$
  • $y^2=12 x^6+11 x^5+16 x^4+16 x^3+13 x^2+16 x+16$
  • $y^2=11 x^6+7 x^5+5 x^4+9 x^3+16 x^2+5 x+12$
  • $y^2=4 x^5+10 x^4+9 x^3+11 x^2+3 x+14$
  • $y^2=x^6+12 x^5+6 x^4+11 x^3+2 x^2+12 x+6$
  • $y^2=2 x^6+3 x^5+2 x^4+x^3+3 x^2+4 x+10$
  • $y^2=13 x^6+3 x^5+5 x^4+3 x^3+13 x^2+12 x+8$
  • $y^2=13 x^6+11 x^5+15 x^4+16 x^3+11 x^2+11 x+8$
  • $y^2=9 x^6+4 x^5+7 x^3+16 x^2+10 x+3$
  • $y^2=15 x^6+7 x^5+9 x^4+5 x^3+9 x^2+14 x+3$
  • $y^2=7 x^6+13 x^5+8 x^4+3 x^3+5 x^2+11 x+13$
  • $y^2=5 x^6+9 x^5+7 x^4+4 x^3+3 x^2+12 x+15$
  • $y^2=8 x^5+7 x^4+x^3+16 x^2+3 x+9$
  • $y^2=13 x^6+16 x^5+10 x^4+12 x^3+12 x^2+13 x+16$
  • $y^2=4 x^6+16 x^5+x^4+15 x^3+4 x^2+x+6$

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{17}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-15 + \sqrt{73}})\).

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.b_q$2$(not in LMFDB)