Properties

Label 2.97.k_by
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

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{97}$
Dimension:  $2$
L-polynomial:  $( 1 - 8 x + 97 x^{2} )( 1 + 18 x + 97 x^{2} )$
  $1 + 10 x + 50 x^{2} + 970 x^{3} + 9409 x^{4}$
Frobenius angles:  $\pm0.366875061252$, $\pm0.866875061252$
Angle rank:  $1$ (numerical)
Jacobians:  $418$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $10440$ $88531200$ $835174453320$ $7837773373440000$ $73740240553766416200$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $108$ $9410$ $915084$ $88533118$ $8587087308$ $832972004930$ $80798270729004$ $7837433941136638$ $760231058254430508$ $73742412689492826050$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 418 curves (of which all are hyperelliptic):

  • $y^2=74 x^6+73 x^5+42 x^4+35 x^3+68 x^2+27 x+5$
  • $y^2=31 x^6+34 x^5+13 x^4+95 x^3+51 x^2+79 x+15$
  • $y^2=58 x^6+38 x^5+47 x^4+71 x^3+17 x^2+78 x+56$
  • $y^2=45 x^6+9 x^5+74 x^4+48 x^3+10 x^2+16 x+60$
  • $y^2=8 x^6+80 x^5+49 x^4+63 x^3+90 x^2+73 x+77$
  • $y^2=83 x^6+18 x^5+20 x^4+29 x^3+86 x^2+6 x+15$
  • $y^2=26 x^6+2 x^5+94 x^4+x^3+27 x^2+89 x+2$
  • $y^2=2 x^6+24 x^5+38 x^4+94 x^3+60 x^2+10 x+19$
  • $y^2=67 x^6+49 x^5+55 x^4+22 x^3+72 x^2+33 x+23$
  • $y^2=52 x^6+5 x^5+75 x^4+75 x^2+5 x+52$
  • $y^2=80 x^6+11 x^5+2 x^4+44 x^3+46 x^2+79 x+68$
  • $y^2=15 x^6+77 x^5+85 x^4+67 x^3+6 x^2+48 x+96$
  • $y^2=74 x^6+30 x^5+70 x^4+16 x^3+56 x^2+74 x+56$
  • $y^2=45 x^6+52 x^5+63 x^4+33 x^3+38 x^2+38 x+21$
  • $y^2=3 x^6+51 x^5+62 x^4+28 x^3+12 x^2+87 x+54$
  • $y^2=11 x^6+13 x^5+20 x^4+85 x^3+6 x^2+61 x+84$
  • $y^2=60 x^6+35 x^5+94 x^4+58 x^3+47 x^2+91 x+93$
  • $y^2=3 x^6+87 x^5+69 x^4+49 x^3+69 x^2+87 x+3$
  • $y^2=15 x^6+73 x^5+88 x^4+49 x^3+64 x^2+4 x$
  • $y^2=50 x^6+56 x^5+37 x^4+6 x^3+x^2+90 x+49$
  • and 398 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{97}$
The isogeny class factors as 1.97.ai $\times$ 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:
Endomorphism algebra over $\overline{\F}_{97}$
The base change of $A$ to $\F_{97^{4}}$ is 1.88529281.cvu 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1}) \)$)$
Remainder of endomorphism lattice by field

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.aba_na$2$(not in LMFDB)
2.97.ak_by$2$(not in LMFDB)
2.97.ba_na$2$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.97.aba_na$2$(not in LMFDB)
2.97.ak_by$2$(not in LMFDB)
2.97.ba_na$2$(not in LMFDB)
2.97.abk_ty$4$(not in LMFDB)
2.97.aq_jy$4$(not in LMFDB)
2.97.a_afa$4$(not in LMFDB)
2.97.a_fa$4$(not in LMFDB)
2.97.q_jy$4$(not in LMFDB)
2.97.bk_ty$4$(not in LMFDB)
2.97.a_afo$8$(not in LMFDB)
2.97.a_fo$8$(not in LMFDB)
2.97.as_it$12$(not in LMFDB)
2.97.ai_abh$12$(not in LMFDB)
2.97.i_abh$12$(not in LMFDB)
2.97.s_it$12$(not in LMFDB)