Properties

Label 2.71.a_aem
Base field $\F_{71}$
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:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $1 - 116 x^{2} + 5041 x^{4}$
Frobenius angles:  $\pm0.0978449860573$, $\pm0.902155013943$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-26}, \sqrt{258})\)
Galois group:  $C_2^2$
Jacobians:  $40$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4926$ $24265476$ $128100477294$ $645582115422864$ $3255243554610073326$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $72$ $4810$ $357912$ $25404934$ $1804229352$ $128100670666$ $9095120158392$ $645753610124734$ $45848500718449032$ $3255243558210265450$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 40 curves (of which all are hyperelliptic):

  • $y^2=6 x^6+30 x^5+8 x^4+15 x^3+12 x^2+48 x+53$
  • $y^2=42 x^6+68 x^5+56 x^4+34 x^3+13 x^2+52 x+16$
  • $y^2=x^6+56 x^5+6 x^4+48 x^3+11 x^2+28 x+35$
  • $y^2=7 x^6+37 x^5+42 x^4+52 x^3+6 x^2+54 x+32$
  • $y^2=15 x^6+27 x^5+19 x^4+70 x^3+34 x^2+67 x+66$
  • $y^2=34 x^6+47 x^5+62 x^4+64 x^3+25 x^2+43 x+36$
  • $y^2=16 x^6+32 x^5+52 x^4+20 x^3+45 x^2+3 x+40$
  • $y^2=41 x^6+11 x^5+9 x^4+69 x^3+31 x^2+21 x+67$
  • $y^2=36 x^6+38 x^5+40 x^4+28 x^3+62 x^2+6 x+62$
  • $y^2=39 x^6+53 x^5+67 x^4+54 x^3+8 x^2+42 x+8$
  • $y^2=52 x^6+8 x^5+4 x^4+6 x^3+8 x^2+57 x+33$
  • $y^2=9 x^6+56 x^5+28 x^4+42 x^3+56 x^2+44 x+18$
  • $y^2=33 x^6+28 x^5+30 x^4+8 x^3+64 x^2+2 x+14$
  • $y^2=18 x^6+54 x^5+68 x^4+56 x^3+22 x^2+14 x+27$
  • $y^2=18 x^6+36 x^5+13 x^3+3 x^2+43 x+8$
  • $y^2=55 x^6+39 x^5+20 x^3+21 x^2+17 x+56$
  • $y^2=18 x^6+58 x^5+34 x^4+51 x^3+15 x^2+16 x+41$
  • $y^2=55 x^6+51 x^5+25 x^4+2 x^3+34 x^2+41 x+3$
  • $y^2=31 x^6+9 x^5+38 x^4+18 x^3+17 x^2+42$
  • $y^2=4 x^6+63 x^5+53 x^4+55 x^3+48 x^2+10$
  • and 20 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{71^{2}}$.

Endomorphism algebra over $\F_{71}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-26}, \sqrt{258})\).
Endomorphism algebra over $\overline{\F}_{71}$
The base change of $A$ to $\F_{71^{2}}$ is 1.5041.aem 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1677}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.71.a_em$4$(not in LMFDB)