Properties

Label 2.61.ai_ba
Base field $\F_{61}$
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:  $\F_{61}$
Dimension:  $2$
L-polynomial:  $1 - 8 x + 26 x^{2} - 488 x^{3} + 3721 x^{4}$
Frobenius angles:  $\pm0.116665938978$, $\pm0.638472987457$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-29 +8 \sqrt{7}})\)
Galois group:  $D_{4}$
Jacobians:  $92$
Isomorphism classes:  200
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $3252$ $13801488$ $51214346388$ $191713930334208$ $713396015530263732$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $54$ $3710$ $225630$ $13846318$ $844659174$ $51520249838$ $3142745468238$ $191707366202974$ $11694146155327638$ $713342912527357790$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 92 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61}$.

Endomorphism algebra over $\F_{61}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-29 +8 \sqrt{7}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.61.i_ba$2$(not in LMFDB)