Properties

Label 2.71.a_fd
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:  $( 1 - 3 x + 71 x^{2} )( 1 + 3 x + 71 x^{2} )$
  $1 + 133 x^{2} + 5041 x^{4}$
Frobenius angles:  $\pm0.443031714434$, $\pm0.556968285566$
Angle rank:  $1$ (numerical)
Jacobians:  $165$
Cyclic group of points:    no
Non-cyclic primes:   $3, 5$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $5175$ $26780625$ $128100625200$ $645367026605625$ $3255243550226229375$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $72$ $5308$ $357912$ $25396468$ $1804229352$ $128100966478$ $9095120158392$ $645753517159588$ $45848500718449032$ $3255243549442577548$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 165 curves (of which all are hyperelliptic):

  • $y^2=17 x^6+56 x^5+14 x^4+12 x^3+49 x^2+5 x+61$
  • $y^2=48 x^6+37 x^5+27 x^4+13 x^3+59 x^2+35 x+1$
  • $y^2=32 x^6+68 x^5+51 x^4+22 x^3+21 x^2+70 x+3$
  • $y^2=11 x^6+50 x^5+2 x^4+12 x^3+5 x^2+64 x+21$
  • $y^2=28 x^6+23 x^5+42 x^4+29 x^3+59 x^2+41 x+66$
  • $y^2=54 x^6+19 x^5+10 x^4+61 x^3+58 x^2+3 x+36$
  • $y^2=23 x^6+23 x^5+5 x^4+20 x^3+38 x^2+22 x+47$
  • $y^2=19 x^6+19 x^5+35 x^4+69 x^3+53 x^2+12 x+45$
  • $y^2=39 x^6+24 x^5+67 x^4+7 x^3+51 x^2+54 x+50$
  • $y^2=60 x^6+26 x^5+43 x^4+49 x^3+2 x^2+23 x+66$
  • $y^2=55 x^6+24 x^5+69 x^4+54 x^3+53 x^2+27 x+51$
  • $y^2=30 x^6+26 x^5+57 x^4+23 x^3+16 x^2+47 x+2$
  • $y^2=12 x^6+46 x^5+67 x^4+34 x^3+15 x^2+52 x+60$
  • $y^2=13 x^6+38 x^5+43 x^4+25 x^3+34 x^2+9 x+65$
  • $y^2=51 x^6+31 x^5+33 x^4+58 x^3+13 x^2+26 x+46$
  • $y^2=2 x^6+4 x^5+18 x^4+51 x^3+20 x^2+40 x+38$
  • $y^2=60 x^6+32 x^5+63 x^4+22 x^3+68 x^2+40 x+37$
  • $y^2=65 x^6+11 x^5+15 x^4+12 x^3+50 x^2+67 x+46$
  • $y^2=26 x^6+2 x^5+43 x^4+15 x^3+x^2+48 x+69$
  • $y^2=40 x^6+14 x^5+17 x^4+34 x^3+7 x^2+52 x+57$
  • and 145 more

Decomposition and endomorphism algebra

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

Endomorphism algebra over $\F_{71}$
The isogeny class factors as 1.71.ad $\times$ 1.71.d 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 $\overline{\F}_{71}$
The base change of $A$ to $\F_{71^{2}}$ is 1.5041.fd 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-11}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.71.ag_fv$2$(not in LMFDB)
2.71.g_fv$2$(not in LMFDB)
2.71.a_afd$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.71.ag_fv$2$(not in LMFDB)
2.71.g_fv$2$(not in LMFDB)
2.71.a_afd$4$(not in LMFDB)
2.71.ad_ack$6$(not in LMFDB)
2.71.d_ack$6$(not in LMFDB)