Properties

Label 2.11.d_ac
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:  $1 + 3 x - 2 x^{2} + 33 x^{3} + 121 x^{4}$
Frobenius angles:  $\pm0.316051259389$, $\pm0.982717926056$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-3}, \sqrt{-35})\)
Galois group:  $C_2^2$
Jacobians:  $2$
Isomorphism classes:  4
Cyclic group of points:    no
Non-cyclic primes:   $2$

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $156$ $13104$ $1971216$ $213280704$ $26029874676$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $15$ $109$ $1476$ $14569$ $161625$ $1766518$ $19488435$ $214334929$ $2358119196$ $25937430829$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 2 curves (of which all are hyperelliptic):

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

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 \(\Q(\sqrt{-3}, \sqrt{-35})\).
Endomorphism algebra over $\overline{\F}_{11}$
The base change of $A$ to $\F_{11^{3}}$ is 1.1331.cu 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-35}) \)$)$

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.ad_ac$2$2.121.an_bw
2.11.ag_bf$3$(not in LMFDB)
2.11.a_n$6$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.11.ad_ac$2$2.121.an_bw
2.11.ag_bf$3$(not in LMFDB)
2.11.a_n$6$(not in LMFDB)
2.11.g_bf$6$(not in LMFDB)
2.11.a_an$12$(not in LMFDB)