Properties

Label 2.97.a_de
Base field $\F_{97}$
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:  $\F_{97}$
Dimension:  $2$
L-polynomial:  $1 + 82 x^{2} + 9409 x^{4}$
Frobenius angles:  $\pm0.319455358770$, $\pm0.680544641230$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{7}, \sqrt{-69})\)
Galois group:  $C_2^2$
Jacobians:  $692$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $9492$ $90098064$ $832970241684$ $7839575263973376$ $73742412703558122132$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $98$ $9574$ $912674$ $88553470$ $8587340258$ $832968478438$ $80798284478114$ $7837433655964414$ $760231058654565218$ $73742412717623418214$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 692 curves (of which all are hyperelliptic):

  • $y^2=21 x^6+75 x^5+42 x^4+4 x^3+57 x^2+52 x+40$
  • $y^2=42 x^6+36 x^5+62 x^4+86 x^3+48 x^2+40 x+92$
  • $y^2=16 x^6+83 x^5+19 x^4+42 x^3+46 x^2+6 x+72$
  • $y^2=95 x^6+34 x^5+21 x^4+45 x^3+40 x^2+46 x+32$
  • $y^2=87 x^6+73 x^5+8 x^4+31 x^3+6 x^2+36 x+63$
  • $y^2=55 x^6+77 x^5+29 x^4+63 x^3+57 x^2+14 x+36$
  • $y^2=81 x^6+94 x^5+48 x^4+24 x^3+91 x^2+70 x+83$
  • $y^2=84 x^6+51 x^5+67 x^4+13 x^3+64 x^2+52 x+48$
  • $y^2=32 x^6+61 x^5+44 x^4+65 x^3+29 x^2+66 x+46$
  • $y^2=4 x^6+51 x^5+19 x^4+67 x^3+3 x^2+53 x+69$
  • $y^2=20 x^6+61 x^5+95 x^4+44 x^3+15 x^2+71 x+54$
  • $y^2=34 x^6+83 x^5+21 x^4+27 x^3+95 x^2+63 x+70$
  • $y^2=41 x^6+85 x^5+87 x^4+80 x^3+22 x^2+4 x+43$
  • $y^2=42 x^6+68 x^5+19 x^4+64 x^3+94 x^2+20 x+1$
  • $y^2=16 x^6+49 x^5+95 x^4+29 x^3+82 x^2+3 x+5$
  • $y^2=33 x^6+45 x^5+23 x^4+7 x^3+96 x^2+87 x+20$
  • $y^2=80 x^6+26 x^5+61 x^4+11 x^3+35 x^2+81 x+63$
  • $y^2=12 x^6+33 x^5+14 x^4+55 x^3+78 x^2+17 x+24$
  • $y^2=4 x^6+87 x^5+54 x^4+36 x^3+82 x^2+13 x+23$
  • $y^2=26 x^6+61 x^5+33 x^4+56 x^3+52 x^2+20 x+61$
  • and 672 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{97^{2}}$.

Endomorphism algebra over $\F_{97}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{7}, \sqrt{-69})\).
Endomorphism algebra over $\overline{\F}_{97}$
The base change of $A$ to $\F_{97^{2}}$ is 1.9409.de 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-483}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.97.a_ade$4$(not in LMFDB)