Properties

Label 2.71.ad_abm
Base field $\F_{71}$
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:  $\F_{71}$
Dimension:  $2$
L-polynomial:  $( 1 - 15 x + 71 x^{2} )( 1 + 12 x + 71 x^{2} )$
  $1 - 3 x - 38 x^{2} - 213 x^{3} + 5041 x^{4}$
Frobenius angles:  $\pm0.150643965450$, $\pm0.752241693036$
Angle rank:  $2$ (numerical)
Jacobians:  $312$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4788$ $24993360$ $127740373488$ $646090852680000$ $3255240893217674508$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $69$ $4957$ $356904$ $25424953$ $1804227879$ $128100997582$ $9095130151449$ $645753521131153$ $45848501227276344$ $3255243550682969077$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 312 curves (of which all are hyperelliptic):

  • $y^2=36 x^6+49 x^5+62 x^4+6 x^3+41 x^2+33 x+22$
  • $y^2=58 x^6+55 x^5+29 x^4+4 x^3+34 x^2+52 x+43$
  • $y^2=29 x^6+63 x^5+60 x^4+49 x^3+47 x^2+49 x+20$
  • $y^2=28 x^6+63 x^5+60 x^4+63 x^3+33 x^2+25 x+7$
  • $y^2=2 x^6+43 x^5+x^4+57 x^3+45 x^2+59 x+3$
  • $y^2=57 x^6+46 x^5+66 x^4+44 x^3+34 x^2+12 x+8$
  • $y^2=6 x^6+38 x^5+65 x^4+36 x^3+19 x^2+19 x+39$
  • $y^2=57 x^6+5 x^5+7 x^4+56 x^3+69 x^2+50 x+17$
  • $y^2=50 x^6+45 x^5+15 x^4+10 x^3+68 x^2+65 x+40$
  • $y^2=32 x^6+8 x^5+44 x^4+48 x^3+43 x^2+32 x+43$
  • $y^2=69 x^6+62 x^5+34 x^4+63 x^3+11 x^2+37 x+25$
  • $y^2=21 x^6+10 x^5+31 x^4+48 x^3+53 x^2+49 x+27$
  • $y^2=44 x^6+25 x^5+64 x^4+2 x^3+5 x^2+12 x+49$
  • $y^2=60 x^6+26 x^5+25 x^4+29 x^3+47 x^2+27 x+36$
  • $y^2=40 x^6+17 x^5+61 x^4+67 x^3+21 x^2+12$
  • $y^2=4 x^6+69 x^5+68 x^4+18 x^3+69 x^2+15 x+66$
  • $y^2=9 x^6+25 x^5+5 x^4+16 x^3+10 x^2+49 x+3$
  • $y^2=43 x^6+70 x^5+27 x^4+67 x^3+37 x^2+11 x+14$
  • $y^2=26 x^6+55 x^5+6 x^4+27 x^3+46 x^2+65 x+32$
  • $y^2=5 x^6+15 x^5+22 x^4+69 x^3+26 x^2+65 x+40$
  • and 292 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.ap $\times$ 1.71.m 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 is a list of all twists of this isogeny class.

TwistExtension degreeCommon base change
2.71.abb_mk$2$(not in LMFDB)
2.71.d_abm$2$(not in LMFDB)
2.71.bb_mk$2$(not in LMFDB)