Properties

Label 2.17.af_j
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:  $1 - 5 x + 9 x^{2} - 85 x^{3} + 289 x^{4}$
Frobenius angles:  $\pm0.0620218782481$, $\pm0.622267387770$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-13 +2 \sqrt{5}})\)
Galois group:  $D_{4}$
Jacobians:  $6$
Isomorphism classes:  6
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $209$ $81301$ $22958441$ $6939934661$ $2017271614864$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $13$ $283$ $4669$ $83091$ $1420758$ $24127147$ $410312629$ $6975922083$ $118587788053$ $2015992774878$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 6 curves (of which all are hyperelliptic):

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 \(\Q(\sqrt{-13 +2 \sqrt{5}})\).

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.f_j$2$(not in LMFDB)