Properties

Label 2.71.a_aec
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:  $1 - 106 x^{2} + 5041 x^{4}$
Frobenius angles:  $\pm0.115871442562$, $\pm0.884128557438$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(i, \sqrt{62})\)
Galois group:  $C_2^2$
Jacobians:  $164$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $4936$ $24364096$ $128100695944$ $645694933238784$ $3255243554178992776$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $72$ $4830$ $357912$ $25409374$ $1804229352$ $128101107966$ $9095120158392$ $645753630229054$ $45848500718449032$ $3255243557348104350$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 164 curves (of which all are hyperelliptic):

  • $y^2=x^6+45 x^5+5 x^4+50 x^3+34 x^2+13 x+59$
  • $y^2=11 x^6+28 x^5+31 x^4+48 x^3+36 x^2+59 x+12$
  • $y^2=6 x^6+54 x^5+4 x^4+52 x^3+39 x^2+58 x+13$
  • $y^2=64 x^6+63 x^5+6 x^4+12 x^3+9 x^2+2 x+55$
  • $y^2=17 x^6+4 x^5+67 x^4+67 x^3+27 x^2+69 x+7$
  • $y^2=48 x^6+28 x^5+43 x^4+43 x^3+47 x^2+57 x+49$
  • $y^2=68 x^6+23 x^5+2 x^4+61 x^3+5 x^2+46 x+52$
  • $y^2=50 x^6+19 x^5+14 x^4+x^3+35 x^2+38 x+9$
  • $y^2=31 x^6+70 x^5+64 x^4+22 x^3+42 x^2+24 x+62$
  • $y^2=4 x^6+64 x^5+22 x^4+12 x^3+10 x^2+26 x+8$
  • $y^2=67 x^6+7 x^5+40 x^4+41 x^3+63 x^2+2 x+45$
  • $y^2=43 x^6+49 x^5+67 x^4+3 x^3+15 x^2+14 x+31$
  • $y^2=11 x^6+18 x^5+69 x^4+28 x^3+46 x^2+4 x+28$
  • $y^2=6 x^6+55 x^5+57 x^4+54 x^3+38 x^2+28 x+54$
  • $y^2=33 x^6+28 x^5+34 x^4+12 x^3+10 x^2+69 x+42$
  • $y^2=26 x^6+51 x^5+50 x^4+68 x^3+60 x^2+64 x+14$
  • $y^2=40 x^6+2 x^5+66 x^4+50 x^3+65 x^2+22 x+27$
  • $y^2=47 x^6+60 x^5+24 x^4+61 x^3+59 x^2+14 x+10$
  • $y^2=45 x^6+65 x^5+26 x^4+x^3+58 x^2+27 x+70$
  • $y^2=40 x^6+69 x^5+57 x^4+15 x^3+36 x^2+66 x+60$
  • and 144 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 \(\Q(i, \sqrt{62})\).
Endomorphism algebra over $\overline{\F}_{71}$
The base change of $A$ to $\F_{71^{2}}$ is 1.5041.aec 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-62}) \)$)$

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.am_gw$4$(not in LMFDB)
2.71.a_ec$4$(not in LMFDB)
2.71.m_gw$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.71.am_gw$4$(not in LMFDB)
2.71.a_ec$4$(not in LMFDB)
2.71.m_gw$4$(not in LMFDB)
2.71.ag_abj$12$(not in LMFDB)
2.71.g_abj$12$(not in LMFDB)