Properties

Label 2.5.ad_m
Base field $\F_{5}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian no

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Invariants

Base field:  $\F_{5}$
Dimension:  $2$
L-polynomial:  $( 1 - 2 x + 5 x^{2} )( 1 - x + 5 x^{2} )$
  $1 - 3 x + 12 x^{2} - 15 x^{3} + 25 x^{4}$
Frobenius angles:  $\pm0.352416382350$, $\pm0.428216853436$
Angle rank:  $2$ (numerical)
Jacobians:  $0$
Isomorphism classes:  2

This isogeny class is not simple, primitive, ordinary, and not supersingular. It is principally polarizable.

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $2$
Slopes:  $[0, 0, 1, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $20$ $1120$ $20720$ $380800$ $9208100$

Point counts of the (virtual) curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $3$ $41$ $162$ $609$ $2943$ $15446$ $78627$ $391969$ $1953018$ $9761201$

Jacobians and polarizations

This isogeny class is principally polarizable, but does not contain a Jacobian.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{5}$.

Endomorphism algebra over $\F_{5}$
The isogeny class factors as 1.5.ac $\times$ 1.5.ab 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
2.5.ab_i$2$2.25.p_ea
2.5.b_i$2$2.25.p_ea
2.5.d_m$2$2.25.p_ea

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

TwistExtension degreeCommon base change
2.5.ab_i$2$2.25.p_ea
2.5.b_i$2$2.25.p_ea
2.5.d_m$2$2.25.p_ea
2.5.af_o$4$2.625.ar_bfk
2.5.ad_g$4$2.625.ar_bfk
2.5.d_g$4$2.625.ar_bfk
2.5.f_o$4$2.625.ar_bfk