Newforms
Hecke characteristic polynomials
The eigenvalue of T=T7โ+3T11โ+5T19โ+7T23โ+9T29โ+11T31โ generates each orbit's coefficient field; on the newspace its characteristic polynomial factors over Q as one irreducible factor per orbit:
Dimensions
| Newforms S2newโ(ฮ0โ(780)) | 8 |
|---|
| Old forms | 149 |
| Cusp forms S2โ(ฮ0โ(780)) | 157 |
|---|
| Eisenstein series E2โ(ฮ0โ(780)) | 23 |
| Modular forms M2โ(ฮ0โ(780)) | 180 |
|---|
Decomposition of the old subspace
S2oldโ(ฮ0โ(780))= S2newโ(ฮ0โ(15))โ6 โ S2newโ(ฮ0โ(20))โ4 โ S2newโ(ฮ0โ(26))โ8 โ S2newโ(ฮ0โ(30))โ4 โ S2newโ(ฮ0โ(39))โ6 โ S2newโ(ฮ0โ(52))โ4 โ S2newโ(ฮ0โ(65))โ6 โ S2newโ(ฮ0โ(78))โ4 โ S2newโ(ฮ0โ(130))โ4 โ S2newโ(ฮ0โ(156))โ2 โ S2newโ(ฮ0โ(195))โ3 โ S2newโ(ฮ0โ(260))โ2 โ S2newโ(ฮ0โ(390))โ2
Provenance
Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.892 s (one thread) and proven: the dimensions are certified, and the characteristic polynomial of T over Z is reconstructed by CRT past a rigorous coefficient bound.
The engine's checks
dim M^+ at levels [1, 2, 3, 4, 5, 6, 10, 12, 13, 15, 20, 26, 30, 39, 52, 60, 65, 78, 130, 156, 195, 260, 390, 780]: [0, 1, 1, 2, 1, 3, 3, 5, 1, 4, 6, 5, 10, 6, 10, 18, 8, 18, 24, 34, 32, 48, 92, 180] (certified at ell = 2147483629)T = [(7, 1), (11, 3), (19, 5), (23, 7), (29, 9), (31, 11)]; h of degree 8 = 1 x 8 (phi(ord eps) x dim S_k^new); 3 primes, 0 rejected
Recompute it yourself
In Sage mode at sagebrush.space (or npx sagebrush --sage):
newform_orbits(780, 2)
With the Rust engine (source), in engine/:
cargo run --release -p sagebrush-web --example atlas -- 780:2 1000
โ 779.2.a ยท 781.2.a โ