Properties

Label 2.41.e_da
Base field $\F_{41}$
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:  $\F_{41}$
Dimension:  $2$
L-polynomial:  $1 + 4 x + 78 x^{2} + 164 x^{3} + 1681 x^{4}$
Frobenius angles:  $\pm0.479394370893$, $\pm0.623056980252$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-19 + \sqrt{2}})\)
Galois group:  $D_{4}$
Jacobians:  $70$
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1928$ $3069376$ $4724002952$ $7975515708416$ $13424198437821448$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $46$ $1822$ $68542$ $2822430$ $115869486$ $4750137982$ $194754287998$ $7984925963454$ $327381902491822$ $13422659321451102$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 70 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{41}$.

Endomorphism algebra over $\F_{41}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-19 + \sqrt{2}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.41.ae_da$2$(not in LMFDB)