Properties

Label 2.97.ar_im
Base field $\F_{97}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple yes
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{97}$
Dimension:  $2$
L-polynomial:  $1 - 17 x + 220 x^{2} - 1649 x^{3} + 9409 x^{4}$
Frobenius angles:  $\pm0.216853147274$, $\pm0.472506156356$
Angle rank:  $2$ (numerical)
Number field:  \(\Q(\sqrt{-1078 +34 \sqrt{185}})\)
Galois group:  $D_{4}$
Jacobians:  $98$
Isomorphism classes:  196
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is simple and 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7964$ $89961344$ $834215493056$ $7837389467680256$ $73743282616120852284$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $81$ $9561$ $914034$ $88528785$ $8587441561$ $832974658302$ $80798293682985$ $7837433338842849$ $760231055707664178$ $73742412685826268361$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 98 curves (of which all are hyperelliptic):

  • $y^2=39 x^6+68 x^5+41 x^4+84 x^3+36 x^2+65 x+64$
  • $y^2=7 x^6+32 x^5+87 x^4+66 x^3+53 x^2+71 x+52$
  • $y^2=29 x^6+34 x^5+40 x^4+40 x^3+95 x^2+79 x+81$
  • $y^2=20 x^6+10 x^5+52 x^4+57 x^3+18 x^2+56 x+1$
  • $y^2=90 x^6+20 x^5+41 x^4+83 x^3+32 x^2+61 x+75$
  • $y^2=56 x^6+95 x^5+82 x^4+37 x^3+32 x^2+35 x+71$
  • $y^2=84 x^6+57 x^5+61 x^4+24 x^3+30 x^2+67 x+82$
  • $y^2=26 x^6+87 x^5+8 x^4+13 x^3+85 x^2+64 x+60$
  • $y^2=63 x^6+79 x^5+4 x^4+60 x^3+22 x^2+31 x+47$
  • $y^2=75 x^6+42 x^5+9 x^4+47 x^3+80 x^2+77 x+85$
  • $y^2=38 x^6+32 x^5+49 x^4+85 x^3+62 x^2+69 x+13$
  • $y^2=78 x^6+85 x^5+45 x^4+82 x^3+15 x^2+92 x+41$
  • $y^2=53 x^6+82 x^5+35 x^3+46 x^2+33 x+9$
  • $y^2=41 x^6+65 x^5+28 x^4+30 x^3+80 x^2+11 x+86$
  • $y^2=41 x^6+37 x^5+84 x^4+62 x^3+82 x^2+49 x+30$
  • $y^2=22 x^6+26 x^5+23 x^4+65 x^3+35 x^2+6 x+21$
  • $y^2=33 x^6+10 x^5+4 x^4+8 x^3+16 x^2+79 x+76$
  • $y^2=17 x^6+x^5+90 x^4+43 x^3+90 x^2+3 x+67$
  • $y^2=23 x^6+70 x^5+31 x^4+44 x^3+55 x^2+52 x+78$
  • $y^2=42 x^6+72 x^5+2 x^4+35 x^3+61 x^2+20 x+89$
  • and 78 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{97}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-1078 +34 \sqrt{185}})\).

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.r_im$2$(not in LMFDB)