Properties

Label 2.67.a_k
Base field $\F_{67}$
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:  $\F_{67}$
Dimension:  $2$
L-polynomial:  $1 + 10 x^{2} + 4489 x^{4}$
Frobenius angles:  $\pm0.261888286667$, $\pm0.738111713333$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(i, \sqrt{31})\)
Galois group:  $C_2^2$
Jacobians:  $759$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4500$ $20250000$ $90458248500$ $406425600000000$ $1822837805536972500$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $68$ $4510$ $300764$ $20168878$ $1350125108$ $90458114830$ $6060711605324$ $406067600523358$ $27206534396294948$ $1822837806522183550$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 759 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{67^{2}}$.

Endomorphism algebra over $\F_{67}$
The endomorphism algebra of this simple isogeny class is \(\Q(i, \sqrt{31})\).
Endomorphism algebra over $\overline{\F}_{67}$
The base change of $A$ to $\F_{67^{2}}$ is 1.4489.k 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-31}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.67.ay_ks$4$(not in LMFDB)
2.67.a_ak$4$(not in LMFDB)
2.67.y_ks$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.67.ay_ks$4$(not in LMFDB)
2.67.a_ak$4$(not in LMFDB)
2.67.y_ks$4$(not in LMFDB)
2.67.am_cz$12$(not in LMFDB)
2.67.m_cz$12$(not in LMFDB)