Properties

Label 2.71.u_jf
Base field $\F_{71}$
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:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $1 + 20 x + 239 x^{2} + 1420 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.663226938123$, $\pm0.745113642058$
Angle rank:  $2$ (numerical)
Number field:  4.0.4544784.1
Galois group:  $D_{4}$
Jacobians:  $20$
Isomorphism classes:  20
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6721$ $25815361$ $127357600084$ $646127739735049$ $3255227494412466001$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $92$ $5120$ $355832$ $25426404$ $1804220452$ $128099503766$ $9095127468652$ $645753509922244$ $45848500550453672$ $3255243553018306400$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 20 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{71}$
The endomorphism algebra of this simple isogeny class is 4.0.4544784.1.

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.71.au_jf$2$(not in LMFDB)