Properties

Label 2.11.e_f
Base field $\F_{11}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple yes
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{11}$
Dimension:  $2$
L-polynomial:  $1 + 4 x + 5 x^{2} + 44 x^{3} + 121 x^{4}$
Frobenius angles:  $\pm0.372703832967$, $\pm0.960629500366$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-3}, \sqrt{-7})\)
Galois group:  $C_2^2$
Jacobians:  $4$
Isomorphism classes:  4
Cyclic group of points:    no
Non-cyclic primes:   $5$

This isogeny class is simple but not geometrically 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $175$ $13825$ $1960000$ $211370425$ $25925029375$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $16$ $116$ $1468$ $14436$ $160976$ $1767638$ $19495856$ $214372036$ $2358033508$ $25937108276$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 4 curves (of which all are hyperelliptic):

  • $y^2=4 x^6+9 x^4+7 x^3+2 x^2+10 x+3$
  • $y^2=8 x^6+10 x^5+9 x^4+8 x^3+2 x^2+8 x+5$
  • $y^2=4 x^6+10 x^5+6 x^4+10 x^3+3 x^2+4 x+5$
  • $y^2=6 x^6+5 x^5+7 x^4+7 x^3+8 x+5$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{11^{3}}$.

Endomorphism algebra over $\F_{11}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-3}, \sqrt{-7})\).
Endomorphism algebra over $\overline{\F}_{11}$
The base change of $A$ to $\F_{11^{3}}$ is 1.1331.cq 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-7}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.11.ae_f$2$2.121.ag_adh
2.11.ai_bm$3$(not in LMFDB)
2.11.a_g$6$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.11.ae_f$2$2.121.ag_adh
2.11.ai_bm$3$(not in LMFDB)
2.11.a_g$6$(not in LMFDB)
2.11.i_bm$6$(not in LMFDB)
2.11.a_ag$12$(not in LMFDB)