Properties

Label 2.97.i_o
Base field $\F_{97}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
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:  $( 1 - 10 x + 97 x^{2} )( 1 + 18 x + 97 x^{2} )$
  $1 + 8 x + 14 x^{2} + 776 x^{3} + 9409 x^{4}$
Frobenius angles:  $\pm0.330505784077$, $\pm0.866875061252$
Angle rank:  $2$ (numerical)
Jacobians:  $597$
Cyclic group of points:    no
Non-cyclic primes:   $2$

This isogeny class is not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $10208$ $88197120$ $835260300512$ $7838487289036800$ $73740887671609941728$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $106$ $9374$ $915178$ $88541182$ $8587162666$ $832971654686$ $80798256971818$ $7837433845175038$ $760231058976021226$ $73742412708050336414$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 597 curves (of which all are hyperelliptic):

  • $y^2=77 x^6+21 x^5+77 x^4+95 x^3+23 x^2+63 x+77$
  • $y^2=87 x^6+66 x^5+49 x^4+26 x^3+34 x^2+79 x+47$
  • $y^2=6 x^6+33 x^5+17 x^4+42 x^3+38 x^2+87 x+81$
  • $y^2=11 x^6+67 x^5+7 x^4+61 x^3+13 x^2+74 x+54$
  • $y^2=39 x^6+24 x^5+5 x^4+78 x^3+89 x^2+7 x+57$
  • $y^2=69 x^6+90 x^5+33 x^4+68 x^3+46 x^2+43 x+88$
  • $y^2=36 x^6+9 x^5+89 x^4+49 x^3+92 x^2+48 x+84$
  • $y^2=64 x^6+88 x^5+22 x^4+40 x^3+57 x^2+20 x+91$
  • $y^2=78 x^6+72 x^5+9 x^4+40 x^3+75 x^2+39 x+42$
  • $y^2=8 x^6+3 x^5+56 x^4+64 x^3+29 x^2+94 x+69$
  • $y^2=18 x^6+19 x^5+28 x^4+14 x^3+83 x^2+14 x+27$
  • $y^2=93 x^6+12 x^5+42 x^4+16 x^3+72 x^2+68 x+87$
  • $y^2=38 x^6+15 x^5+11 x^4+4 x^3+23 x^2+52 x+78$
  • $y^2=56 x^6+41 x^5+72 x^4+56 x^3+90 x^2+87 x+81$
  • $y^2=58 x^6+66 x^5+11 x^4+40 x^2+11 x+62$
  • $y^2=32 x^6+30 x^5+95 x^4+7 x^3+12 x^2+34 x+21$
  • $y^2=72 x^6+80 x^5+96 x^4+7 x^3+26 x^2+94 x+65$
  • $y^2=96 x^6+92 x^5+54 x^4+2 x^3+x^2+44 x+84$
  • $y^2=73 x^6+48 x^5+91 x^4+77 x^3+9 x^2+91 x+66$
  • $y^2=63 x^6+43 x^5+86 x^4+93 x^3+71 x^2+92 x+46$
  • and 577 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{97}$
The isogeny class factors as 1.97.ak $\times$ 1.97.s and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

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.abc_ok$2$(not in LMFDB)
2.97.ai_o$2$(not in LMFDB)
2.97.bc_ok$2$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.97.abc_ok$2$(not in LMFDB)
2.97.ai_o$2$(not in LMFDB)
2.97.bc_ok$2$(not in LMFDB)
2.97.as_ko$4$(not in LMFDB)
2.97.ac_ek$4$(not in LMFDB)
2.97.c_ek$4$(not in LMFDB)
2.97.s_ko$4$(not in LMFDB)