Properties

Label 2.5.ae_o
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 yes

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Invariants

Base field:  $\F_{5}$
Dimension:  $2$
L-polynomial:  $( 1 - 2 x + 5 x^{2} )^{2}$
  $1 - 4 x + 14 x^{2} - 20 x^{3} + 25 x^{4}$
Frobenius angles:  $\pm0.352416382350$, $\pm0.352416382350$
Angle rank:  $1$ (numerical)
Jacobians:  $1$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $16$ $1024$ $21904$ $409600$ $9265936$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $2$ $38$ $170$ $654$ $2962$ $15158$ $78010$ $392734$ $1957922$ $9764678$

Jacobians and polarizations

This isogeny class contains the Jacobian of 1 curve (which is hyperelliptic), and hence is principally polarizable:

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 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-1}) \)$)$

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.a_g$2$2.25.m_di
2.5.e_o$2$2.25.m_di
2.5.c_ab$3$2.125.bs_bcg

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

TwistExtension degreeCommon base change
2.5.a_g$2$2.25.m_di
2.5.e_o$2$2.25.m_di
2.5.c_ab$3$2.125.bs_bcg
2.5.ai_ba$4$2.625.bc_cdq
2.5.ag_s$4$2.625.bc_cdq
2.5.ac_c$4$2.625.bc_cdq
2.5.a_ag$4$2.625.bc_cdq
2.5.c_c$4$2.625.bc_cdq
2.5.g_s$4$2.625.bc_cdq
2.5.i_ba$4$2.625.bc_cdq
2.5.ac_ab$6$(not in LMFDB)
2.5.a_ai$8$(not in LMFDB)
2.5.a_i$8$(not in LMFDB)
2.5.ae_l$12$(not in LMFDB)
2.5.e_l$12$(not in LMFDB)