Properties

Label 2.61.a_es
Base field $\F_{61}$
Dimension $2$
$p$-rank $0$
Ordinary no
Supersingular yes
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{61}$
Dimension:  $2$
L-polynomial:  $( 1 + 61 x^{2} )^{2}$
  $1 + 122 x^{2} + 3721 x^{4}$
Frobenius angles:  $\pm0.5$, $\pm0.5$
Angle rank:  $0$ (numerical)
Jacobians:  $65$

This isogeny class is not simple, primitive, not ordinary, and supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

This isogeny class is supersingular.

$p$-rank:  $0$
Slopes:  $[1/2, 1/2, 1/2, 1/2]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $3844$ $14776336$ $51520828324$ $191501314560000$ $713342913352075204$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $62$ $3966$ $226982$ $13830958$ $844596302$ $51521282286$ $3142742836022$ $191707257613918$ $11694146092834142$ $713342915041267806$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 65 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61^{2}}$.

Endomorphism algebra over $\F_{61}$
The isogeny class factors as 1.61.a 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-61}) \)$)$
Endomorphism algebra over $\overline{\F}_{61}$
The base change of $A$ to $\F_{61^{2}}$ is 1.3721.es 2 and its endomorphism algebra is $\mathrm{M}_{2}(B)$, where $B$ is the quaternion algebra over \(\Q\) ramified at $61$ and $\infty$.

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.61.a_acj$3$(not in LMFDB)
2.61.a_aes$4$(not in LMFDB)
2.61.a_acj$6$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.61.a_acj$3$(not in LMFDB)
2.61.a_aes$4$(not in LMFDB)
2.61.a_acj$6$(not in LMFDB)
2.61.a_a$8$(not in LMFDB)
2.61.a_cj$12$(not in LMFDB)