Properties

Label 4.5.ac_ah_ac_cy
Base field $\F_{5}$
Dimension $4$
$p$-rank $4$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes

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Invariants

Base field:  $\F_{5}$
Dimension:  $4$
L-polynomial:  $( 1 - x - 4 x^{2} - 5 x^{3} + 25 x^{4} )^{2}$
  $1 - 2 x - 7 x^{2} - 2 x^{3} + 76 x^{4} - 10 x^{5} - 175 x^{6} - 250 x^{7} + 625 x^{8}$
Frobenius angles:  $\pm0.0948835201023$, $\pm0.0948835201023$, $\pm0.761550186769$, $\pm0.761550186769$
Angle rank:  $1$ (numerical)
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

Newton polygon

This isogeny class is ordinary.

$p$-rank:  $4$
Slopes:  $[0, 0, 0, 0, 1, 1, 1, 1]$

Point counts

Point counts of the abelian variety

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $256$ $200704$ $157351936$ $168401895424$ $89434395064576$

Point counts of the (virtual) curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $4$ $8$ $70$ $688$ $2924$ $15842$ $79244$ $390048$ $1963150$ $9773528$

Jacobians and polarizations

This isogeny class is principally polarizable and contains no Jacobian of a hyperelliptic curve, but it is unknown whether it contains a Jacobian of a non-hyperelliptic curve.

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{5^{3}}$.

Endomorphism algebra over $\F_{5}$
The isogeny class factors as 2.5.ab_ae 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-3}, \sqrt{-19})\)$)$
Endomorphism algebra over $\overline{\F}_{5}$
The base change of $A$ to $\F_{5^{3}}$ is 1.125.ao 4 and its endomorphism algebra is $\mathrm{M}_{4}($\(\Q(\sqrt{-19}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
4.5.a_aj_a_ce$2$(not in LMFDB)
4.5.c_ah_c_cy$2$(not in LMFDB)
4.5.b_f_ao_ao$3$(not in LMFDB)
4.5.e_ba_cm_id$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
4.5.a_aj_a_ce$2$(not in LMFDB)
4.5.c_ah_c_cy$2$(not in LMFDB)
4.5.b_f_ao_ao$3$(not in LMFDB)
4.5.e_ba_cm_id$3$(not in LMFDB)
4.5.a_j_a_ce$4$(not in LMFDB)
4.5.ae_ba_acm_id$6$(not in LMFDB)
4.5.ad_j_as_ba$6$(not in LMFDB)
4.5.ac_u_abc_ft$6$(not in LMFDB)
4.5.ab_f_ao_o$6$(not in LMFDB)
4.5.ab_f_o_ao$6$(not in LMFDB)
4.5.a_s_a_fb$6$(not in LMFDB)
4.5.b_f_o_o$6$(not in LMFDB)
4.5.c_u_bc_ft$6$(not in LMFDB)
4.5.d_j_s_ba$6$(not in LMFDB)
4.5.ac_c_i_abx$12$(not in LMFDB)
4.5.ab_an_e_di$12$(not in LMFDB)
4.5.a_as_a_fb$12$(not in LMFDB)
4.5.a_a_a_abf$12$(not in LMFDB)
4.5.b_an_ae_di$12$(not in LMFDB)
4.5.c_c_ai_abx$12$(not in LMFDB)
4.5.ab_ae_j_l$15$(not in LMFDB)
4.5.a_a_a_bf$24$(not in LMFDB)
4.5.b_ae_aj_l$30$(not in LMFDB)