Properties

Label 2.97.a_agz
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:  $1 - 181 x^{2} + 9409 x^{4}$
Frobenius angles:  $\pm0.0585951244730$, $\pm0.941404875527$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-13}, \sqrt{15})\)
Galois group:  $C_2^2$
Jacobians:  $12$
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $9229$ $85174441$ $832971184276$ $7834965238284921$ $73742412694074247189$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $98$ $9048$ $912674$ $88501396$ $8587340258$ $832970363622$ $80798284478114$ $7837433559679588$ $760231058654565218$ $73742412698655668328$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 12 curves (of which all are hyperelliptic):

  • $y^2=23 x^6+34 x^5+12 x^4+26 x^3+82 x^2+41 x+93$
  • $y^2=49 x^6+49 x^5+22 x^4+27 x^3+29 x^2+16 x+74$
  • $y^2=42 x^6+64 x^5+73 x^4+60 x^3+92 x^2+89 x+8$
  • $y^2=81 x^6+45 x^5+64 x^4+28 x^3+20 x^2+51 x+59$
  • $y^2=73 x^6+12 x^5+87 x^4+28 x^3+43 x^2+24 x+90$
  • $y^2=26 x^6+20 x^5+91 x^4+26 x^3+23 x^2+46 x+65$
  • $y^2=70 x^6+19 x^5+10 x^4+43 x^3+36 x^2+60 x+30$
  • $y^2=33 x^6+23 x^5+75 x^4+81 x^3+83 x^2+51 x+55$
  • $y^2=52 x^6+47 x^5+76 x^4+88 x^3+25 x^2+18 x+50$
  • $y^2=29 x^6+60 x^5+93 x^4+55 x^3+29 x^2+74 x+81$
  • $y^2=5 x^6+6 x^5+59 x^4+93 x^3+3 x^2+48 x+53$
  • $y^2=42 x^6+22 x^5+93 x^4+68 x^2+53 x+70$

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 \(\Q(\sqrt{-13}, \sqrt{15})\).
Endomorphism algebra over $\overline{\F}_{97}$
The base change of $A$ to $\F_{97^{2}}$ is 1.9409.agz 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-195}) \)$)$

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_gz$4$(not in LMFDB)