Properties

Label 2.61.a_acv
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:  $1 - 73 x^{2} + 3721 x^{4}$
Frobenius angles:  $\pm0.147909504823$, $\pm0.852090495177$
Angle rank:  $1$ (numerical)
Number field:  \(\Q(i, \sqrt{195})\)
Galois group:  $C_2^2$
Jacobians:  $84$
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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $3649$ $13315201$ $51520800244$ $191765857682025$ $713342911773740329$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $62$ $3576$ $226982$ $13850068$ $844596302$ $51521226126$ $3142742836022$ $191707359451108$ $11694146092834142$ $713342911884598056$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 84 curves (of which all are hyperelliptic):

  • $y^2=10 x^6+18 x^5+54 x^4+41 x^3+41 x^2+12 x+1$
  • $y^2=20 x^6+36 x^5+47 x^4+21 x^3+21 x^2+24 x+2$
  • $y^2=23 x^6+43 x^5+25 x^4+40 x^3+5 x^2+27 x+44$
  • $y^2=46 x^6+25 x^5+50 x^4+19 x^3+10 x^2+54 x+27$
  • $y^2=14 x^6+54 x^5+15 x^3+24 x+29$
  • $y^2=37 x^6+55 x^5+17 x^4+51 x^3+48 x^2+10 x+34$
  • $y^2=52 x^6+39 x^5+23 x^4+44 x^3+39 x^2+53 x+7$
  • $y^2=43 x^6+17 x^5+46 x^4+27 x^3+17 x^2+45 x+14$
  • $y^2=57 x^6+24 x^5+32 x^4+43 x^3+55 x^2+37 x+37$
  • $y^2=53 x^6+48 x^5+3 x^4+25 x^3+49 x^2+13 x+13$
  • $y^2=35 x^6+12 x^5+15 x^4+36 x^3+60 x^2+x+37$
  • $y^2=9 x^6+24 x^5+30 x^4+11 x^3+59 x^2+2 x+13$
  • $y^2=53 x^6+30 x^5+9 x^4+38 x^3+40 x^2+50 x+37$
  • $y^2=45 x^6+60 x^5+18 x^4+15 x^3+19 x^2+39 x+13$
  • $y^2=47 x^6+54 x^5+14 x^4+51 x^3+42 x^2+35 x+21$
  • $y^2=33 x^6+47 x^5+28 x^4+41 x^3+23 x^2+9 x+42$
  • $y^2=15 x^6+17 x^5+8 x^4+2 x^3+26 x^2+2$
  • $y^2=30 x^6+34 x^5+16 x^4+4 x^3+52 x^2+4$
  • $y^2=34 x^6+23 x^5+x^4+12 x^3+57 x^2+6 x+51$
  • $y^2=7 x^6+46 x^5+2 x^4+24 x^3+53 x^2+12 x+41$
  • and 64 more

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 \(\Q(i, \sqrt{195})\).
Endomorphism algebra over $\overline{\F}_{61}$
The base change of $A$ to $\F_{61^{2}}$ is 1.3721.acv 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-195}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.61.ao_gp$4$(not in LMFDB)
2.61.a_cv$4$(not in LMFDB)
2.61.o_gp$4$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.61.ao_gp$4$(not in LMFDB)
2.61.a_cv$4$(not in LMFDB)
2.61.o_gp$4$(not in LMFDB)
2.61.ah_am$12$(not in LMFDB)
2.61.h_am$12$(not in LMFDB)