Properties

Label 2.43.au_gx
Base field $\F_{43}$
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:  $\F_{43}$
Dimension:  $2$
L-polynomial:  $1 - 20 x + 179 x^{2} - 860 x^{3} + 1849 x^{4}$
Frobenius angles:  $\pm0.0853946760970$, $\pm0.310510497030$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-65 +20 \sqrt{7}})\)
Galois group:  $D_{4}$
Jacobians:  $4$
Isomorphism classes:  4
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1149$ $3342441$ $6334027956$ $11691327169881$ $21610086049060989$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $24$ $1808$ $79668$ $3419716$ $146998944$ $6321224702$ $271818034848$ $11688203656708$ $502592681255724$ $21611482855023728$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 4 curves (of which all are hyperelliptic):

  • $y^2=28 x^6+34 x^5+37 x^4+34 x^3+39 x^2+7 x+17$
  • $y^2=37 x^6+40 x^5+31 x^4+9 x^3+37 x^2+42 x+6$
  • $y^2=33 x^6+16 x^5+24 x^4+5 x^3+17 x^2+3$
  • $y^2=17 x^6+22 x^5+16 x^4+42 x^3+25 x^2+19 x+8$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{43}$.

Endomorphism algebra over $\F_{43}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-65 +20 \sqrt{7}})\).

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.43.u_gx$2$(not in LMFDB)