Newforms
Hecke characteristic polynomials
The eigenvalue of T=T7โ+3T11โ+5T13โ+7T17โ+9T19โ+11T23โ generates each orbit's coefficient field; on the newspace its characteristic polynomial factors over Q as one irreducible factor per orbit:
Dimensions
| Newforms S4newโ(ฮ0โ(120)) | 6 |
|---|
| Old forms | 58 |
| Cusp forms S4โ(ฮ0โ(120)) | 64 |
|---|
| Eisenstein series E4โ(ฮ0โ(120)) | 16 |
| Modular forms M4โ(ฮ0โ(120)) | 80 |
|---|
Decomposition of the old subspace
S4oldโ(ฮ0โ(120))= S4newโ(ฮ0โ(5))โ8 โ S4newโ(ฮ0โ(6))โ6 โ S4newโ(ฮ0โ(8))โ4 โ S4newโ(ฮ0โ(10))โ6 โ S4newโ(ฮ0โ(12))โ4 โ S4newโ(ฮ0โ(15))โ4 โ S4newโ(ฮ0โ(20))โ4 โ S4newโ(ฮ0โ(24))โ2 โ S4newโ(ฮ0โ(30))โ3 โ S4newโ(ฮ0โ(40))โ2 โ S4newโ(ฮ0โ(60))โ2
Provenance
Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.255 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, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120]: [1, 2, 2, 3, 3, 5, 5, 7, 9, 8, 12, 16, 22, 22, 42, 80] (certified at ell = 2147483629)T = [(7, 1), (11, 3), (13, 5), (17, 7), (19, 9), (23, 11)]; h of degree 6 = 1 x 6 (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(120, 4)
With the Rust engine (source), in engine/:
cargo run --release -p sagebrush-web --example atlas -- 120:4 1000
โ 119.4.a ยท 121.4.a โ