Invariants
| Base field: | $\F_{19}$ |
| Dimension: | $2$ |
| L-polynomial: | $1 - 4 x + 36 x^{2} - 76 x^{3} + 361 x^{4}$ |
| Frobenius angles: | $\pm0.329500503504$, $\pm0.516419341233$ |
| Angle rank: | $2$ (numerical) |
| Number field: | 4.0.2453760.1 |
| Galois group: | $D_{4}$ |
| Jacobians: | $16$ |
| Cyclic group of points: | yes |
This isogeny class is simple and 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
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $A(\F_{q^r})$ | $318$ | $152004$ | $48015774$ | $16942365840$ | $6129574516398$ |
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
|---|---|---|---|---|---|---|---|---|---|---|
| $C(\F_{q^r})$ | $16$ | $418$ | $7000$ | $130006$ | $2475496$ | $47045266$ | $893816464$ | $16983432286$ | $322689335920$ | $6131073538978$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 16 curves (of which all are hyperelliptic):
- $y^2=12 x^6+7 x^5+11 x^4+2 x^3+12 x^2+7 x+5$
- $y^2=2 x^6+2 x^5+17 x^4+10 x^3+18 x^2+8 x+18$
- $y^2=18 x^6+15 x^5+17 x^4+9 x^3+7 x^2+7 x+2$
- $y^2=12 x^6+13 x^5+8 x^4+8 x^3+9 x^2+6 x+16$
- $y^2=3 x^6+12 x^5+18 x^4+12 x^3+13 x^2+7 x+5$
- $y^2=3 x^6+10 x^5+11 x^4+5 x^3+15 x^2+x+10$
- $y^2=11 x^6+6 x^5+15 x^4+14 x^3+8 x^2+10 x+2$
- $y^2=9 x^6+6 x^5+14 x^4+14 x^3+4 x^2+14 x+4$
- $y^2=12 x^6+18 x^5+8 x^4+15 x^3+x^2+14 x+13$
- $y^2=18 x^6+x^5+16 x^4+12 x^2+13$
- $y^2=2 x^6+8 x^5+17 x^4+2 x^3+5 x^2+15 x+13$
- $y^2=17 x^6+12 x^5+2 x^4+5 x^3+13 x^2+6 x+2$
- $y^2=10 x^6+4 x^5+2 x^4+2 x^3+17 x^2+9 x+17$
- $y^2=15 x^6+15 x^5+3 x^4+7 x^3+17 x^2+18 x$
- $y^2=17 x^6+15 x^5+5 x^4+6 x^3+8 x^2+10 x+13$
- $y^2=14 x^6+14 x^5+12 x^4+16 x^3+3 x^2+17 x+3$
Decomposition and endomorphism algebra
All geometric endomorphisms are defined over $\F_{19}$.
Endomorphism algebra over $\F_{19}$| The endomorphism algebra of this simple isogeny class is 4.0.2453760.1. |
Base change
This is a primitive isogeny class.
Twists
Below is a list of all twists of this isogeny class.
| Twist | Extension degree | Common base change |
|---|---|---|
| 2.19.e_bk | $2$ | (not in LMFDB) |