Abelian variety isogeny class 5.2.ai_bh_ado_hj_alu over $\F_{2}$

• Label: 5.2.ai_bh_ado_hj_alu
• Base field: $\F_{2}$
• Dimension: $5$
• $p$-rank: $4$
• Ordinary: no
• Supersingular: no
• Simple: no
• Geometrically simple: no
• Primitive: yes
• Principally polarizable: yes
• Contains a Jacobian: no

Invariants

Base field:	$\F_{2}$
Dimension:	$5$
L-polynomial:	$( 1 - 2 x + 2 x^{2} )( 1 - 3 x + 5 x^{2} - 6 x^{3} + 4 x^{4} )^{2}$
	$1 - 8 x + 33 x^{2} - 92 x^{3} + 191 x^{4} - 306 x^{5} + 382 x^{6} - 368 x^{7} + 264 x^{8} - 128 x^{9} + 32 x^{10}$
Frobenius angles:	$\pm0.123548644961$, $\pm0.123548644961$, $\pm0.250000000000$, $\pm0.456881978294$, $\pm0.456881978294$
Angle rank:	$1$ (numerical)
Jacobians:	$0$

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

Newton polygon

$p$-rank:	$4$
Slopes:	$[0, 0, 0, 0, 1/2, 1/2, 1, 1, 1, 1]$

Point counts

Point counts of the abelian variety

$r$	$1$	$2$	$3$	$4$	$5$
$A(\F_{q^r})$	$1$	$1805$	$75088$	$731025$	$37864361$

Point counts of the (virtual) curve

$r$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$	$9$	$10$
$C(\F_{q^r})$	$-5$	$7$	$13$	$11$	$35$	$109$	$191$	$259$	$481$	$1147$

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 $\F_{2^{12}}$.

Endomorphism algebra over $\F_{2}$

The isogeny class factors as 1.2.ac $\times$ 2.2.ad_f^2 and its endomorphism algebra is a direct product of the endomorphism algebras for each isotypic factor. The endomorphism algebra for each factor is:

• 1.2.ac : \(\Q(\sqrt{-1}) \).
• 2.2.ad_f^2 : $\mathrm{M}_{2}($\(\Q(\sqrt{-3}, \sqrt{5})\)$)$

Endomorphism algebra over $\overline{\F}_{2}$

The base change of $A$ to $\F_{2^{12}}$ is 1.4096.h^4 $\times$ 1.4096.ey. The endomorphism algebra for each factor is:

• 1.4096.h^4 : $\mathrm{M}_{4}($\(\Q(\sqrt{-15}) \)$)$
• 1.4096.ey : the quaternion algebra over \(\Q\) ramified at $2$ and $\infty$.

Remainder of endomorphism lattice by field

• Endomorphism algebra over $\F_{2^{2}}$
  The base change of $A$ to $\F_{2^{2}}$ is 1.4.a $\times$ 2.4.b_ad^2. The endomorphism algebra for each factor is:

  • 1.4.a : \(\Q(\sqrt{-1}) \).
  • 2.4.b_ad^2 : $\mathrm{M}_{2}($\(\Q(\sqrt{-3}, \sqrt{5})\)$)$
• Endomorphism algebra over $\F_{2^{3}}$
  The base change of $A$ to $\F_{2^{3}}$ is 1.8.e $\times$ 2.8.a_l^2. The endomorphism algebra for each factor is:

  • 1.8.e : \(\Q(\sqrt{-1}) \).
  • 2.8.a_l^2 : $\mathrm{M}_{2}($\(\Q(\sqrt{-3}, \sqrt{5})\)$)$
• Endomorphism algebra over $\F_{2^{4}}$
  The base change of $A$ to $\F_{2^{4}}$ is 1.16.i $\times$ 2.16.ah_bh^2. The endomorphism algebra for each factor is:

  • 1.16.i : the quaternion algebra over \(\Q\) ramified at $2$ and $\infty$.
  • 2.16.ah_bh^2 : $\mathrm{M}_{2}($\(\Q(\sqrt{-3}, \sqrt{5})\)$)$
• Endomorphism algebra over $\F_{2^{6}}$
  The base change of $A$ to $\F_{2^{6}}$ is 1.64.a $\times$ 1.64.l^4. The endomorphism algebra for each factor is:

  • 1.64.a : \(\Q(\sqrt{-1}) \).
  • 1.64.l^4 : $\mathrm{M}_{4}($\(\Q(\sqrt{-15}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

Twist	Extension degree	Common base change
5.2.ae_j_aq_x_abe	$2$	(not in LMFDB)
5.2.ac_d_ac_ab_g	$2$	(not in LMFDB)
5.2.c_d_c_ab_ag	$2$	(not in LMFDB)
5.2.e_j_q_x_be	$2$	(not in LMFDB)
5.2.i_bh_do_hj_lu	$2$	(not in LMFDB)
5.2.af_m_ar_r_as	$3$	(not in LMFDB)
5.2.ac_a_e_f_as	$3$	(not in LMFDB)
5.2.ac_d_ac_ab_g	$3$	(not in LMFDB)
5.2.b_a_b_f_g	$3$	(not in LMFDB)
5.2.e_j_q_x_be	$3$	(not in LMFDB)