Invariants
| Base field: | $\F_{41}$ |
| Dimension: | $2$ |
| L-polynomial: | $1 - 2 x^{2} + 1681 x^{4}$ |
| Frobenius angles: | $\pm0.246117787144$, $\pm0.753882212856$ |
| Angle rank: | $1$ (numerical) |
| Number field: | \(\Q(\sqrt{-5}, \sqrt{21})\) |
| Galois group: | $C_2^2$ |
| Jacobians: | $284$ |
| 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
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $A(\F_{q^r})$ | $1680$ | $2822400$ | $4750114320$ | $8003919974400$ | $13422659281962000$ |
| $r$ | $1$ | $2$ | $3$ | $4$ | $5$ | $6$ | $7$ | $8$ | $9$ | $10$ |
|---|---|---|---|---|---|---|---|---|---|---|
| $C(\F_{q^r})$ | $42$ | $1678$ | $68922$ | $2832478$ | $115856202$ | $4750124398$ | $194754273882$ | $7984913979838$ | $327381934393962$ | $13422659253771598$ |
Jacobians and polarizations
This isogeny class is principally polarizable and contains the Jacobians of 284 curves (of which all are hyperelliptic):
- $y^2=36 x^6+2 x^5+2 x^4+13 x^3+19 x^2+39 x$
- $y^2=11 x^6+12 x^5+12 x^4+37 x^3+32 x^2+29 x$
- $y^2=39 x^6+15 x^5+30 x^4+34 x^3+25 x^2+7 x+13$
- $y^2=37 x^6+25 x^5+18 x^4+14 x^3+5 x^2+18 x+13$
- $y^2=17 x^6+27 x^5+26 x^4+2 x^3+30 x^2+26 x+37$
- $y^2=7 x^6+37 x^5+10 x^4+32 x^3+6 x+30$
- $y^2=x^6+17 x^5+19 x^4+28 x^3+36 x+16$
- $y^2=22 x^6+22 x^5+21 x^4+28 x^3+22 x^2+34 x+20$
- $y^2=15 x^6+20 x^5+25 x^4+32 x^3+x^2+14 x+11$
- $y^2=8 x^6+38 x^5+27 x^4+28 x^3+6 x^2+2 x+25$
- $y^2=10 x^6+15 x^5+27 x^4+9 x^3+35 x^2+11 x+10$
- $y^2=19 x^6+8 x^5+39 x^4+13 x^3+5 x^2+25 x+19$
- $y^2=14 x^6+x^5+34 x^4+9 x^3+7 x^2+23 x+6$
- $y^2=2 x^6+6 x^5+40 x^4+13 x^3+x^2+15 x+36$
- $y^2=37 x^6+3 x^5+33 x^4+14 x^2+34 x$
- $y^2=17 x^6+18 x^5+34 x^4+2 x^2+40 x$
- $y^2=24 x^6+13 x^5+4 x^4+15 x^3+28 x^2+22 x+32$
- $y^2=38 x^6+20 x^5+23 x^4+37 x^3+27 x^2+4 x+5$
- $y^2=13 x^6+36 x^5+18 x^4+2 x^3+15 x^2+7 x+2$
- $y^2=37 x^6+11 x^5+26 x^4+12 x^3+8 x^2+x+12$
- and 264 more
Decomposition and endomorphism algebra
All geometric endomorphisms are defined over $\F_{41^{2}}$.
Endomorphism algebra over $\F_{41}$| The endomorphism algebra of this simple isogeny class is \(\Q(\sqrt{-5}, \sqrt{21})\). |
| The base change of $A$ to $\F_{41^{2}}$ is 1.1681.ac 2 and its endomorphism algebra is $\mathrm{M}_{2}($\(\Q(\sqrt{-105}) \)$)$ |
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 |
|---|---|---|
| 2.41.a_c | $4$ | (not in LMFDB) |