Properties

Label 2.43.a_g
Base field $\F_{43}$
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:  $\F_{43}$
Dimension:  $2$
L-polynomial:  $1 + 6 x^{2} + 1849 x^{4}$
Frobenius angles:  $\pm0.261112861004$, $\pm0.738887138996$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{5}, \sqrt{-23})\)
Galois group:  $C_2^2$
Jacobians:  $218$
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1856$ $3444736$ $6321329984$ $11713259831296$ $21611482413859136$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $44$ $1862$ $79508$ $3426126$ $147008444$ $6321296918$ $271818611108$ $11688187132318$ $502592611936844$ $21611482514434022$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 218 curves (of which all are hyperelliptic):

  • $y^2=15 x^6+x^5+25 x^4+39 x^3+31 x^2+22$
  • $y^2=2 x^6+3 x^5+32 x^4+31 x^3+7 x^2+23$
  • $y^2=32 x^6+28 x^5+31 x^4+41 x^3+12 x^2+8 x+24$
  • $y^2=10 x^6+41 x^5+7 x^4+37 x^3+36 x^2+24 x+29$
  • $y^2=3 x^6+20 x^5+12 x^4+20 x^3+41 x+25$
  • $y^2=38 x^6+8 x^5+28 x^4+34 x^3+24 x^2+5 x+5$
  • $y^2=8 x^6+5 x^5+3 x^4+2 x^3+8 x^2+7 x+39$
  • $y^2=24 x^6+15 x^5+9 x^4+6 x^3+24 x^2+21 x+31$
  • $y^2=21 x^6+31 x^5+31 x^4+19 x^3+14 x^2+34 x+14$
  • $y^2=20 x^6+7 x^5+7 x^4+14 x^3+42 x^2+16 x+42$
  • $y^2=37 x^6+40 x^5+25 x^4+17 x^3+3 x^2+14 x+4$
  • $y^2=25 x^6+34 x^5+32 x^4+8 x^3+9 x^2+42 x+12$
  • $y^2=35 x^6+24 x^5+7 x^4+20 x^3+31 x^2+5 x$
  • $y^2=19 x^6+29 x^5+21 x^4+17 x^3+7 x^2+15 x$
  • $y^2=22 x^6+26 x^5+12 x^4+x^3+36 x^2+19 x+35$
  • $y^2=30 x^6+41 x^5+30 x^4+18 x^3+22 x^2+19 x+8$
  • $y^2=4 x^6+37 x^5+4 x^4+11 x^3+23 x^2+14 x+24$
  • $y^2=35 x^6+29 x^5+21 x^4+x^3+42 x^2+35 x+6$
  • $y^2=19 x^6+x^5+20 x^4+3 x^3+40 x^2+19 x+18$
  • $y^2=39 x^6+29 x^5+24 x^4+9 x^3+2 x^2+22 x+1$
  • and 198 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{43^{2}}$.

Endomorphism algebra over $\F_{43}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{5}, \sqrt{-23})\).
Endomorphism algebra over $\overline{\F}_{43}$
The base change of $A$ to $\F_{43^{2}}$ is 1.1849.g 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-115}) \)$)$

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.a_ag$4$(not in LMFDB)