Properties

Label 2.163.abt_bfu
Base field $\F_{163}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

Related objects

Downloads

Learn more

Invariants

Base field:  $\F_{163}$
Dimension:  $2$
L-polynomial:  $( 1 - 25 x + 163 x^{2} )( 1 - 20 x + 163 x^{2} )$
  $1 - 45 x + 826 x^{2} - 7335 x^{3} + 26569 x^{4}$
Frobenius angles:  $\pm0.0652307277549$, $\pm0.213555132351$
Angle rank:  $2$ (numerical)
Jacobians:  $40$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $20016$ $696076416$ $18748356375744$ $498319460689752576$ $13239671720157033432336$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $119$ $26197$ $4329128$ $705923161$ $115063927769$ $18755372172598$ $3057125227966523$ $498311413555096753$ $81224760521236925144$ $13239635966914544781397$

Jacobians and polarizations

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

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{163}$.

Endomorphism algebra over $\F_{163}$
The isogeny class factors as 1.163.az $\times$ 1.163.au 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
2.163.af_ags$2$(not in LMFDB)
2.163.f_ags$2$(not in LMFDB)
2.163.bt_bfu$2$(not in LMFDB)
2.163.am_gk$3$(not in LMFDB)
2.163.ad_ao$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.163.af_ags$2$(not in LMFDB)
2.163.f_ags$2$(not in LMFDB)
2.163.bt_bfu$2$(not in LMFDB)
2.163.am_gk$3$(not in LMFDB)
2.163.ad_ao$3$(not in LMFDB)
2.163.abl_zq$6$(not in LMFDB)
2.163.abc_ss$6$(not in LMFDB)
2.163.d_ao$6$(not in LMFDB)
2.163.m_gk$6$(not in LMFDB)
2.163.bc_ss$6$(not in LMFDB)
2.163.bl_zq$6$(not in LMFDB)