Properties

Label 2.61.a_adl
Base field $\F_{61}$
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:  $\F_{61}$
Dimension:  $2$
L-polynomial:  $1 - 89 x^{2} + 3721 x^{4}$
Frobenius angles:  $\pm0.119874499213$, $\pm0.880125500787$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(\sqrt{-33}, \sqrt{211})\)
Galois group:  $C_2^2$
Jacobians:  $18$
Isomorphism classes:  24
Cyclic group of points:    yes

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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $3633$ $13198689$ $51520662900$ $191694076601769$ $713342913033372153$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $62$ $3544$ $226982$ $13844884$ $844596302$ $51520951438$ $3142742836022$ $191707367921764$ $11694146092834142$ $713342914403861704$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 18 curves (of which all are hyperelliptic):

  • $y^2=43 x^6+23 x^5+6 x^4+13 x^3+34 x^2+54 x+39$
  • $y^2=22 x^6+14 x^5+17 x^4+18 x^3+49 x^2+58 x+24$
  • $y^2=44 x^6+28 x^5+34 x^4+36 x^3+37 x^2+55 x+48$
  • $y^2=27 x^6+9 x^5+45 x^4+37 x^3+40 x^2+41 x+28$
  • $y^2=58 x^6+60 x^5+12 x^4+7 x^3+26 x^2+58 x+11$
  • $y^2=21 x^6+11 x^5+22 x^4+7 x^3+43 x^2+24 x+22$
  • $y^2=51 x^6+55 x^5+6 x^4+4 x^3+58 x^2+29 x+47$
  • $y^2=46 x^6+2 x^5+43 x^4+30 x^3+7 x^2+34 x+10$
  • $y^2=31 x^6+4 x^5+25 x^4+60 x^3+14 x^2+7 x+20$
  • $y^2=24 x^6+59 x^5+41 x^4+34 x^3+59 x^2+50 x+1$
  • $y^2=42 x^6+14 x^5+8 x^4+39 x^3+43 x^2+8 x+9$
  • $y^2=23 x^6+28 x^5+16 x^4+17 x^3+25 x^2+16 x+18$
  • $y^2=41 x^6+25 x^5+25 x^4+22 x^3+41 x^2+48 x+38$
  • $y^2=21 x^6+50 x^5+50 x^4+44 x^3+21 x^2+35 x+15$
  • $y^2=46 x^6+7 x^5+51 x^4+44 x^3+39 x^2+37 x+39$
  • $y^2=31 x^6+14 x^5+41 x^4+27 x^3+17 x^2+13 x+17$
  • $y^2=15 x^6+30 x^5+59 x^4+10 x^3+55 x^2+34 x+23$
  • $y^2=30 x^6+60 x^5+57 x^4+20 x^3+49 x^2+7 x+46$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{61^{2}}$.

Endomorphism algebra over $\F_{61}$
The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-33}, \sqrt{211})\).
Endomorphism algebra over $\overline{\F}_{61}$
The base change of $A$ to $\F_{61^{2}}$ is 1.3721.adl 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-6963}) \)$)$

Base change

This is a primitive isogeny class.

Twists

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

TwistExtension degreeCommon base change
2.61.a_dl$4$(not in LMFDB)