Properties

Label 1.397.c
Base field $\F_{397}$
Dimension $1$
$p$-rank $1$
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:  $\F_{397}$
Dimension:  $1$
L-polynomial:  $1 + 2 x + 397 x^{2}$
Frobenius angles:  $\pm0.515982229621$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-11}) \)
Galois group:  $C_2$
Jacobians:  $30$

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:  $1$
Slopes:  $[0, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $400$ $158400$ $62568400$ $24840288000$ $9861718522000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $400$ $158400$ $62568400$ $24840288000$ $9861718522000$ $3915101753323200$ $1554295347767131600$ $617055253358620032000$ $244970935601957979955600$ $97253461433823004079352000$

Jacobians and polarizations

This isogeny class contains the Jacobians of 30 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{397}$.

Endomorphism algebra over $\F_{397}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-11}) \).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
1.397.ac$2$(not in LMFDB)