Properties

Label 1.49.a
Base field $\F_{7^{2}}$
Dimension $1$
$p$-rank $0$
Ordinary no
Supersingular yes
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{7^{2}}$
Dimension:  $1$
L-polynomial:  $1 + 49 x^{2}$
Frobenius angles:  $\pm0.5$
Angle rank:  $0$ (numerical)
Number field:  \(\Q(\sqrt{-1}) \)
Galois group:  $C_2$
Jacobians:  $2$
Isomorphism classes:  2
Cyclic group of points:    yes

This isogeny class is simple and geometrically simple, primitive, not ordinary, and supersingular. It is principally polarizable and contains a Jacobian.

Newton polygon

This isogeny class is supersingular.

$p$-rank:  $0$
Slopes:  $[1/2, 1/2]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $50$ $2500$ $117650$ $5760000$ $282475250$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $50$ $2500$ $117650$ $5760000$ $282475250$ $13841522500$ $678223072850$ $33232919040000$ $1628413597910450$ $79792266862562500$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 2 curves (of which 0 are hyperelliptic):

where $a$ is a root of the Conway polynomial.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{7^{4}}$.

Endomorphism algebra over $\F_{7^{2}}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-1}) \).
Endomorphism algebra over $\overline{\F}_{7^{2}}$
The base change of $A$ to $\F_{7^{4}}$ is the simple isogeny class 1.2401.du and its endomorphism algebra is the quaternion algebra over \(\Q\) ramified at $7$ and $\infty$.

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
1.49.ao$4$(not in LMFDB)
1.49.o$4$(not in LMFDB)