Properties

Label 2.19.ae_g
Base field $\F_{19}$
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:  $\F_{19}$
Dimension:  $2$
L-polynomial:  $( 1 - 8 x + 19 x^{2} )( 1 + 4 x + 19 x^{2} )$
  $1 - 4 x + 6 x^{2} - 76 x^{3} + 361 x^{4}$
Frobenius angles:  $\pm0.130073469147$, $\pm0.651731832911$
Angle rank:  $2$ (numerical)
Jacobians:  $44$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $288$ $129024$ $45559584$ $17020846080$ $6139978364448$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $16$ $358$ $6640$ $130606$ $2479696$ $47043286$ $893940784$ $16984025566$ $322687638160$ $6131069428678$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 44 curves (of which all are hyperelliptic):

  • $y^2=10 x^6+14 x^5+7 x^4+14 x^3+15 x^2+11$
  • $y^2=11 x^6+x^5+8 x^4+17 x^3+10 x^2+2$
  • $y^2=15 x^6+3 x^4+13 x^3+6 x^2+5 x+8$
  • $y^2=9 x^6+11 x^5+13 x^3+9 x+4$
  • $y^2=4 x^6+12 x^5+3 x^3+10 x^2+16 x$
  • $y^2=x^5+12 x^4+13 x^2+15 x+16$
  • $y^2=9 x^6+9 x^5+6 x^4+18 x^3+12 x^2+13 x+8$
  • $y^2=16 x^6+x^5+5 x^4+9 x^3+11 x^2+9 x+14$
  • $y^2=11 x^6+3 x^5+3 x^4+2 x^3+5 x^2+13 x+13$
  • $y^2=12 x^6+12 x^5+9 x^4+2 x^3+14 x^2+3 x+15$
  • $y^2=18 x^6+13 x^5+15 x^4+2 x^3+10 x^2+4 x+10$
  • $y^2=2 x^5+16 x^4+16 x^3+5 x^2+16$
  • $y^2=17 x^6+3 x^5+15 x^4+5 x^3+15 x^2+14 x$
  • $y^2=9 x^6+7 x^5+3 x^4+17 x^3+7 x^2+8 x+13$
  • $y^2=9 x^6+15 x^5+7 x^4+10 x^3+3 x^2+8 x+9$
  • $y^2=10 x^6+12 x^5+17 x^4+14 x^3+13 x^2+17 x+9$
  • $y^2=9 x^5+17 x^4+14 x^3+18 x^2+11 x+18$
  • $y^2=12 x^6+18 x^5+17 x^4+5 x^3+17 x^2+18 x+12$
  • $y^2=x^6+4 x^5+17 x^4+4 x^3+6 x^2+4 x+6$
  • $y^2=15 x^6+7 x^5+15 x^4+4 x^2+14 x$
  • and 24 more

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{19}$.

Endomorphism algebra over $\F_{19}$
The isogeny class factors as 1.19.ai $\times$ 1.19.e 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 are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.19.am_cs$2$(not in LMFDB)
2.19.e_g$2$(not in LMFDB)
2.19.m_cs$2$(not in LMFDB)
2.19.f_bq$3$(not in LMFDB)
2.19.l_co$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.19.am_cs$2$(not in LMFDB)
2.19.e_g$2$(not in LMFDB)
2.19.m_cs$2$(not in LMFDB)
2.19.f_bq$3$(not in LMFDB)
2.19.l_co$3$(not in LMFDB)
2.19.al_co$6$(not in LMFDB)
2.19.af_bq$6$(not in LMFDB)
2.19.ad_k$6$(not in LMFDB)
2.19.ad_bi$6$(not in LMFDB)
2.19.d_k$6$(not in LMFDB)
2.19.d_bi$6$(not in LMFDB)