Properties

Label 2.23.m_de
Base field $\F_{23}$
Dimension $2$
$p$-rank $2$
Ordinary yes
Supersingular no
Simple no
Geometrically simple no
Primitive yes
Principally polarizable yes
Contains a Jacobian yes

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Invariants

Base field:  $\F_{23}$
Dimension:  $2$
L-polynomial:  $( 1 + 6 x + 23 x^{2} )^{2}$
  $1 + 12 x + 82 x^{2} + 276 x^{3} + 529 x^{4}$
Frobenius angles:  $\pm0.715122617226$, $\pm0.715122617226$
Angle rank:  $1$ (numerical)
Jacobians:  $14$
Cyclic group of points:    no
Non-cyclic primes:   $2, 3, 5$

This isogeny class is not 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

$r$ $1$ $2$ $3$ $4$ $5$
$A(\F_{q^r})$ $900$ $291600$ $143280900$ $78848640000$ $41411155522500$

Point counts of the curve

$r$ $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $10$
$C(\F_{q^r})$ $36$ $550$ $11772$ $281758$ $6433956$ $148006150$ $3405058812$ $78310269118$ $1801151591076$ $41426534107750$

Jacobians and polarizations

This isogeny class is principally polarizable and contains the Jacobians of 14 curves (of which all are hyperelliptic):

  • $y^2=16 x^6+5 x^4+8 x^3+5 x^2+16$
  • $y^2=9 x^6+17 x^5+17 x^4+17 x^2+17 x+9$
  • $y^2=9 x^6+4 x^4+6 x^3+4 x^2+9$
  • $y^2=18 x^6+10 x^5+8 x^4+15 x^3+18 x^2+19 x+16$
  • $y^2=17 x^6+15 x^4+15 x^2+17$
  • $y^2=3 x^6+2 x^4+2 x^2+3$
  • $y^2=9 x^6+6 x^4+9 x^3+6 x^2+9$
  • $y^2=14 x^6+6 x^5+7 x^4+7 x^3+15 x^2+13 x+19$
  • $y^2=17 x^5+19 x^4+10 x^3+19 x^2+17 x$
  • $y^2=x^6+17 x^5+11 x^4+17 x^3+11 x^2+17 x+1$
  • $y^2=22 x^6+7 x^5+x^4+20 x^3+2 x^2+5 x+15$
  • $y^2=6 x^6+22 x^5+14 x^4+10 x^3+11 x^2+11 x+4$
  • $y^2=11 x^6+8 x^5+15 x^4+9 x^3+20 x^2+4 x+15$
  • $y^2=2 x^6+16 x^5+9 x^4+x^2+9 x+3$

Decomposition and endomorphism algebra

All geometric endomorphisms are defined over $\F_{23}$.

Endomorphism algebra over $\F_{23}$
The isogeny class factors as 1.23.g 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-14}) \)$)$

Base change

This is a primitive isogeny class.

Twists

Below are some of the twists of this isogeny class.

TwistExtension degreeCommon base change
2.23.am_de$2$(not in LMFDB)
2.23.a_k$2$(not in LMFDB)
2.23.ag_n$3$(not in LMFDB)

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

TwistExtension degreeCommon base change
2.23.am_de$2$(not in LMFDB)
2.23.a_k$2$(not in LMFDB)
2.23.ag_n$3$(not in LMFDB)
2.23.a_ak$4$(not in LMFDB)
2.23.g_n$6$(not in LMFDB)