Properties

Label 2.19.h_by
Base field $\F_{19}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian no

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Invariants

Base field:  $\F_{19}$
Dimension:  $2$
L-polynomial:  $( 1 + 3 x + 19 x^{2} )( 1 + 4 x + 19 x^{2} )$
  $1 + 7 x + 50 x^{2} + 133 x^{3} + 361 x^{4}$
Frobenius angles:  $\pm0.611823923823$, $\pm0.651731832911$
Angle rank:  $2$ (numerical)
Jacobians:  $0$
Isomorphism classes:  4
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

Newton polygon

This isogeny class is ordinary.

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

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $552$ $150144$ $44970336$ $16999303680$ $6144094760952$

Point counts of the (virtual) curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $27$ $413$ $6552$ $130441$ $2481357$ $47025686$ $893845623$ $16984013521$ $322686638568$ $6131061912653$

Jacobians and polarizations

This isogeny class is principally polarizable, but does not contain a Jacobian.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{19}$.

Endomorphism algebra over $\F_{19}$
The isogeny class factors as 1.19.d $\times$ 1.19.e 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
2.19.ah_by$2$(not in LMFDB)
2.19.ab_ba$2$(not in LMFDB)
2.19.b_ba$2$(not in LMFDB)