Properties

Label 2.83.a_cq
Base field $\F_{83}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{83}$
Dimension:  $2$
L-polynomial:  $1 + 68 x^{2} + 6889 x^{4}$
Frobenius angles:  $\pm0.317172587130$, $\pm0.682827412870$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{2}, \sqrt{-13})\)
Galois group:  $C_2^2$
Jacobians:  $343$
Cyclic group of points:    no
Non-cyclic primes:   $7$

This isogeny class is simple but not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $6958$ $48413764$ $326939282446$ $2253161277810576$ $15516041193965005918$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $84$ $7026$ $571788$ $47476630$ $3939040644$ $326938191522$ $27136050989628$ $2252292254380894$ $186940255267540404$ $15516041200724158386$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 343 curves (of which all are hyperelliptic):

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{83^{2}}$.

Endomorphism algebra over $\F_{83}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{2}, \sqrt{-13})\).
Endomorphism algebra over $\overline{\F}_{83}$
The base change of $A$ to $\F_{83^{2}}$ is 1.6889.cq 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-13}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.83.a_acq$4$(not in LMFDB)
2.83.ao_du$8$(not in LMFDB)
2.83.o_du$8$(not in LMFDB)