Atlas › Modular forms › Weight 2 › Level 70 › 70.2.a

Newspace 70.2.a: $S_{2}^{\mathrm{new}}(\Gamma_0(70))$

Newforms

Label	Dim	Coefficient field	Trace form	AL signs	Sign	CM	Elliptic curve
70.2.a.a	1	$\mathbb{Q}$	$q + q^{2} + q^{4} - q^{5} - q^{7} + O(q^{8})$	− + +	$+1$		70a1 rank 0

Hecke characteristic polynomials

The eigenvalue of $T = T_{3} + T_{11}$ generates each orbit's coefficient field; on the newspace its characteristic polynomial factors over $\mathbb{Q}$ as one irreducible factor per orbit:

Orbit	Characteristic polynomial of $T$
70.2.a.a	$x - 4$

Dimensions

Newforms $S_{2}^{\mathrm{new}}(\Gamma_0(70))$	1
Old forms	8
Cusp forms $S_{2}(\Gamma_0(70))$	9
Eisenstein series $E_{2}(\Gamma_0(70))$	7
Modular forms $M_{2}(\Gamma_0(70))$	16

Decomposition of the old subspace

$S_{2}^{\mathrm{old}}(\Gamma_0(70)) =$ $S_{2}^{\mathrm{new}}(\Gamma_0(14))^{\oplus 2}$ $\oplus$ $S_{2}^{\mathrm{new}}(\Gamma_0(35))^{\oplus 2}$

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.113 s (one thread) and proven: the dimensions are certified, and the characteristic polynomial of $T$ over $\mathbb{Z}$ is reconstructed by CRT past a rigorous coefficient bound.

The engine's checks

dim M^+ at levels [1, 2, 5, 7, 10, 14, 35, 70]: [0, 1, 1, 1, 3, 4, 6, 16] (certified at ell = 2147483629)
T = [(3, 1), (11, 1)]; h of degree 1 = 1 x 1 (phi(ord eps) x dim S_k^new); 1 primes, 0 rejected

Open in the notebook · JSON · stored data

Recompute it yourself

In Sage mode at sagebrush.space (or npx sagebrush --sage):

newform_orbits(70, 2)

With the Rust engine (source), in engine/:

cargo run --release -p sagebrush-web --example atlas -- 70:2 1000

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