Properties

Label 2.17.f_i
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:  $1 + 5 x + 8 x^{2} + 85 x^{3} + 289 x^{4}$
Frobenius angles:  $\pm0.374029230508$, $\pm0.959304102825$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-3}, \sqrt{-43})\)
Galois group:  $C_2^2$
Jacobians:  $5$
Isomorphism classes:  5
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $388$ $80704$ $25441936$ $6934410496$ $2015602095268$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $23$ $281$ $5174$ $83025$ $1419583$ $24123422$ $410378719$ $6975837409$ $118588438358$ $2015991136361$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 5 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{17^{3}}$.

Endomorphism algebra over $\F_{17}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-3}, \sqrt{-43})\).
Endomorphism algebra over $\overline{\F}_{17}$
The base change of $A$ to $\F_{17^{3}}$ is 1.4913.fa 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-43}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.17.af_i$2$(not in LMFDB)
2.17.ak_ch$3$(not in LMFDB)
2.17.a_j$6$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.17.af_i$2$(not in LMFDB)
2.17.ak_ch$3$(not in LMFDB)
2.17.a_j$6$(not in LMFDB)
2.17.k_ch$6$(not in LMFDB)
2.17.a_aj$12$(not in LMFDB)