Properties

Label 2.97.ay_lc
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:  $1 - 24 x + 288 x^{2} - 2328 x^{3} + 9409 x^{4}$
Frobenius angles:  $\pm0.0805057840767$, $\pm0.419494215923$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\zeta_{8})\)
Galois group:  $C_2^2$
Jacobians:  $88$
Isomorphism classes:  213
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7346$ $88519300$ $832906294994$ $7835666472490000$ $73740415438593917906$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $74$ $9410$ $912602$ $88509318$ $8587107674$ $832972004930$ $80798305663562$ $7837433749213438$ $760231058457614474$ $73742412689492826050$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 88 curves (of which all are hyperelliptic):

  • $y^2=42 x^6+88 x^5+37 x^3+7 x^2+68 x+37$
  • $y^2=8 x^6+59 x^5+11 x^4+48 x^3+57 x^2+14 x+10$
  • $y^2=67 x^6+89 x^5+78 x^4+9 x^3+70 x^2+93 x+86$
  • $y^2=68 x^6+34 x^5+64 x^4+73 x^3+44 x^2+27 x+3$
  • $y^2=81 x^6+82 x^5+33 x^4+2 x^3+51 x^2+46 x+38$
  • $y^2=73 x^6+74 x^5+58 x^4+21 x^3+90 x^2+2 x+83$
  • $y^2=85 x^6+24 x^5+88 x^4+94 x^2+91 x+55$
  • $y^2=83 x^6+74 x^5+31 x^4+22 x^3+32 x^2+66 x+51$
  • $y^2=85 x^6+95 x^5+41 x^4+25 x^3+62 x^2+20 x+88$
  • $y^2=x^6+80 x^5+18 x^4+65 x^3+6 x^2+59 x+67$
  • $y^2=15 x^6+65 x^5+93 x^4+32 x^3+47 x^2+46 x+23$
  • $y^2=83 x^6+x^5+37 x^4+60 x^3+34 x^2+87 x+39$
  • $y^2=31 x^6+60 x^5+42 x^4+20 x^3+84 x^2+81 x+82$
  • $y^2=65 x^6+96 x^5+60 x^4+51 x^3+69 x^2+53 x+18$
  • $y^2=41 x^6+80 x^5+61 x^4+71 x^3+10 x^2+46 x+77$
  • $y^2=56 x^6+95 x^5+19 x^4+88 x^3+14 x^2+89 x+6$
  • $y^2=x^6+77 x^5+38 x^4+94 x^3+90 x^2+80 x+15$
  • $y^2=54 x^6+68 x^5+60 x^4+88 x^3+12 x^2+87 x+66$
  • $y^2=81 x^6+13 x^5+14 x^4+4 x^3+59 x^2+95 x+9$
  • $y^2=73 x^6+64 x^5+28 x^4+56 x^3+78 x^2+3 x+35$
  • and 68 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{97^{4}}$.

Endomorphism algebra over $\F_{97}$
The endomorphism algebra of this simple isogeny class is \(\Q(\zeta_{8})\).
Endomorphism algebra over $\overline{\F}_{97}$
The base change of $A$ to $\F_{97^{4}}$ is 1.88529281.aoty 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-2}) \)$)$
Remainder of endomorphism lattice by field
  • Endomorphism algebra over $\F_{97^{2}}$
    The base change of $A$ to $\F_{97^{2}}$ is the simple isogeny class 2.9409.a_aoty and its endomorphism algebra is \(\Q(\zeta_{8})\).

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.97.y_lc$2$(not in LMFDB)
2.97.au_li$8$(not in LMFDB)
2.97.a_adq$8$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.97.y_lc$2$(not in LMFDB)
2.97.au_li$8$(not in LMFDB)
2.97.a_adq$8$(not in LMFDB)
2.97.a_dq$8$(not in LMFDB)
2.97.u_li$8$(not in LMFDB)
2.97.ak_d$24$(not in LMFDB)
2.97.k_d$24$(not in LMFDB)