Properties

Label 2.199.aby_bnf
Base field $\F_{199}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{199}$
Dimension:  $2$
L-polynomial:  $( 1 - 27 x + 199 x^{2} )( 1 - 23 x + 199 x^{2} )$
  $1 - 50 x + 1019 x^{2} - 9950 x^{3} + 39601 x^{4}$
Frobenius angles:  $\pm0.0936959350875$, $\pm0.196619630811$
Angle rank:  $2$ (numerical)
Jacobians:  $12$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $30621$ $1550065641$ $62088089585904$ $2459423877760491849$ $97393991078214868601901$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $150$ $39140$ $7878600$ $1568270884$ $312080606250$ $62103856973006$ $12358664467959750$ $2459374193055320644$ $489415464124909579800$ $97393677359686357343300$

Jacobians and polarizations

This isogeny class contains the Jacobians of 12 curves (of which all are hyperelliptic), and hence is principally polarizable:

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{199}$.

Endomorphism algebra over $\F_{199}$
The isogeny class factors as 1.199.abb $\times$ 1.199.ax and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.199.ae_aip$2$(not in LMFDB)
2.199.e_aip$2$(not in LMFDB)
2.199.by_bnf$2$(not in LMFDB)