Properties

Label 2.64.a_abp
Base field $\F_{2^{6}}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{2^{6}}$
Dimension:  $2$
L-polynomial:  $( 1 - 13 x + 64 x^{2} )( 1 + 13 x + 64 x^{2} )$
  $1 - 41 x^{2} + 4096 x^{4}$
Frobenius angles:  $\pm0.198106042756$, $\pm0.801893957244$
Angle rank:  $1$ (numerical)
Jacobians:  $426$
Isomorphism classes:  12240

This isogeny class is not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4056$ $16451136$ $68719911624$ $281693525577984$ $1152921502463163576$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $65$ $4015$ $262145$ $16790239$ $1073741825$ $68720346511$ $4398046511105$ $281474959033279$ $18014398509481985$ $1152921500319480175$

Jacobians and polarizations

This isogeny class contains the Jacobians of 426 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{2^{12}}$.

Endomorphism algebra over $\F_{2^{6}}$
The isogeny class factors as 1.64.an $\times$ 1.64.n and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:
Endomorphism algebra over $\overline{\F}_{2^{6}}$
The base change of $A$ to $\F_{2^{12}}$ is 1.4096.abp 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-87}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.64.aba_ll$2$(not in LMFDB)
2.64.ba_ll$2$(not in LMFDB)
2.64.a_bp$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.64.aba_ll$2$(not in LMFDB)
2.64.ba_ll$2$(not in LMFDB)
2.64.a_bp$4$(not in LMFDB)
2.64.an_eb$6$(not in LMFDB)
2.64.n_eb$6$(not in LMFDB)