Properties

Label 2.83.a_eg
Base field $\F_{83}$
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:  $\F_{83}$
Dimension:  $2$
L-polynomial:  $1 + 110 x^{2} + 6889 x^{4}$
Frobenius angles:  $\pm0.365284270737$, $\pm0.634715729263$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{14}, \sqrt{-69})\)
Galois group:  $C_2^2$
Jacobians:  $636$
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $7000$ $49000000$ $326939431000$ $2252451600000000$ $15516041183566735000$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $84$ $7110$ $571788$ $47461678$ $3939040644$ $326938488630$ $27136050989628$ $2252292416340958$ $186940255267540404$ $15516041179927616550$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 636 curves (of which all are hyperelliptic):

  • $y^2=53 x^6+12 x^5+45 x^4+37 x^3+7 x^2+59 x+65$
  • $y^2=23 x^6+24 x^5+7 x^4+74 x^3+14 x^2+35 x+47$
  • $y^2=22 x^6+67 x^5+59 x^4+70 x^3+29 x^2+64 x+34$
  • $y^2=44 x^6+51 x^5+35 x^4+57 x^3+58 x^2+45 x+68$
  • $y^2=4 x^6+18 x^5+11 x^4+20 x^3+7 x^2+16 x+81$
  • $y^2=36 x^6+73 x^5+58 x^4+56 x^3+13 x^2+58 x+19$
  • $y^2=72 x^6+63 x^5+33 x^4+29 x^3+26 x^2+33 x+38$
  • $y^2=20 x^6+26 x^5+32 x^4+72 x^3+18 x^2+28 x+56$
  • $y^2=14 x^6+56 x^5+60 x^4+38 x^3+21 x^2+60 x+10$
  • $y^2=28 x^6+29 x^5+37 x^4+76 x^3+42 x^2+37 x+20$
  • $y^2=76 x^6+60 x^5+36 x^4+29 x^3+41 x^2+67 x+36$
  • $y^2=69 x^6+37 x^5+72 x^4+58 x^3+82 x^2+51 x+72$
  • $y^2=62 x^6+18 x^5+54 x^4+45 x^3+68 x+56$
  • $y^2=41 x^6+36 x^5+25 x^4+7 x^3+53 x+29$
  • $y^2=77 x^6+74 x^5+41 x^4+50 x^3+76 x^2+41 x+47$
  • $y^2=71 x^6+65 x^5+82 x^4+17 x^3+69 x^2+82 x+11$
  • $y^2=6 x^6+36 x^5+72 x^4+9 x^3+28 x^2+46 x+79$
  • $y^2=12 x^6+72 x^5+61 x^4+18 x^3+56 x^2+9 x+75$
  • $y^2=18 x^6+44 x^5+43 x^4+46 x^3+78 x^2+70 x+60$
  • $y^2=36 x^6+5 x^5+3 x^4+9 x^3+73 x^2+57 x+37$
  • and 616 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{83^{2}}$.

Endomorphism algebra over $\F_{83}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{14}, \sqrt{-69})\).
Endomorphism algebra over $\overline{\F}_{83}$
The base change of $A$ to $\F_{83^{2}}$ is 1.6889.eg 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-966}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.83.a_aeg$4$(not in LMFDB)