Properties

Label 2.71.a_bq
Base field $\F_{71}$
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:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 - 10 x + 71 x^{2} )( 1 + 10 x + 71 x^{2} )$
  $1 + 42 x^{2} + 5041 x^{4}$
Frobenius angles:  $\pm0.297788873486$, $\pm0.702211126514$
Angle rank:  $1$ (numerical)
Jacobians:  $256$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $5084$ $25847056$ $128099722844$ $646176400000000$ $3255243554609637404$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $72$ $5126$ $357912$ $25428318$ $1804229352$ $128099161766$ $9095120158392$ $645753494514238$ $45848500718449032$ $3255243558209393606$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 256 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71^{2}}$.

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.ak $\times$ 1.71.k 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 $\overline{\F}_{71}$
The base change of $A$ to $\F_{71^{2}}$ is 1.5041.bq 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-46}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.71.au_ji$2$(not in LMFDB)
2.71.u_ji$2$(not in LMFDB)
2.71.a_abq$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.71.au_ji$2$(not in LMFDB)
2.71.u_ji$2$(not in LMFDB)
2.71.a_abq$4$(not in LMFDB)
2.71.ak_bd$6$(not in LMFDB)
2.71.k_bd$6$(not in LMFDB)