Properties

Label 2.43.a_da
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:  $1 + 78 x^{2} + 1849 x^{4}$
Frobenius angles:  $\pm0.430807909064$, $\pm0.569192090936$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{2}, \sqrt{-41})\)
Galois group:  $C_2^2$
Jacobians:  $106$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $1928$ $3717184$ $6321404936$ $11671898285056$ $21611482146557768$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $44$ $2006$ $79508$ $3414030$ $147008444$ $6321446822$ $271818611108$ $11688202566814$ $502592611936844$ $21611481979831286$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 106 curves (of which all are hyperelliptic):

  • $y^2=10 x^6+33 x^5+11 x^4+3 x^3+12 x^2+41 x+39$
  • $y^2=30 x^6+13 x^5+33 x^4+9 x^3+36 x^2+37 x+31$
  • $y^2=9 x^6+10 x^5+15 x^4+41 x^3+38 x^2+29 x+13$
  • $y^2=27 x^6+30 x^5+2 x^4+37 x^3+28 x^2+x+39$
  • $y^2=6 x^6+40 x^5+18 x^4+9 x^3+7 x^2+27 x+28$
  • $y^2=18 x^6+34 x^5+11 x^4+27 x^3+21 x^2+38 x+41$
  • $y^2=35 x^6+35 x^5+2 x^4+17 x^3+11 x^2+4 x+32$
  • $y^2=19 x^6+19 x^5+6 x^4+8 x^3+33 x^2+12 x+10$
  • $y^2=25 x^6+25 x^5+29 x^4+10 x^2+38 x+21$
  • $y^2=32 x^6+32 x^5+x^4+30 x^2+28 x+20$
  • $y^2=40 x^6+11 x^5+18 x^4+27 x^3+21 x^2+7 x+30$
  • $y^2=34 x^6+33 x^5+11 x^4+38 x^3+20 x^2+21 x+4$
  • $y^2=28 x^6+26 x^5+34 x^4+16 x^2+24 x+25$
  • $y^2=12 x^6+17 x^5+18 x^4+30 x^3+30 x^2+29 x+33$
  • $y^2=36 x^6+8 x^5+11 x^4+4 x^3+4 x^2+x+13$
  • $y^2=9 x^6+8 x^5+17 x^4+28 x^3+40 x^2+34 x+9$
  • $y^2=37 x^6+28 x^5+10 x^4+28 x^3+7 x^2+24 x+16$
  • $y^2=25 x^6+41 x^5+30 x^4+41 x^3+21 x^2+29 x+5$
  • $y^2=17 x^6+24 x^5+39 x^4+26 x^3+39 x^2+22 x+15$
  • $y^2=8 x^6+29 x^5+31 x^4+35 x^3+31 x^2+23 x+2$
  • and 86 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 \(\Q(\sqrt{2}, \sqrt{-41})\).
Endomorphism algebra over $\overline{\F}_{43}$
The base change of $A$ to $\F_{43^{2}}$ is 1.1849.da 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-82}) \)$)$

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_ada$4$(not in LMFDB)
2.43.ae_i$8$(not in LMFDB)
2.43.e_i$8$(not in LMFDB)