Atlas › Modular forms › Weight 2 › Level 426 › 426.2.a

Newspace 426.2.a: $S_{2}^{\mathrm{new}}(\Gamma_0(426))$

Newforms

Label	Dim	Coefficient field	Trace form	AL signs	Sign	Elliptic curve
426.2.a.a	1	$\mathbb{Q}$	$q - q^{2} - q^{3} + q^{4} - 2q^{5} + q^{6} + 2q^{7} + O(q^{8})$	+ + +	$-1$	426b1 rank 1
426.2.a.b	1	$\mathbb{Q}$	$q - q^{2} + q^{3} + q^{4} + 3q^{5} - q^{6} - q^{7} + O(q^{8})$	+ − +	$+1$	426c1 rank 0
426.2.a.c	1	$\mathbb{Q}$	$q + q^{2} + q^{3} + q^{4} + q^{5} + q^{6} + 3q^{7} + O(q^{8})$	− − −	$+1$	426a1 rank 0
426.2.a.d	2	$\mathbb{Q}(\sqrt{2})$	$2q - 2q^{2} - 2q^{3} + 2q^{4} + 2q^{5} + 2q^{6} - 2q^{7} + O(q^{8})$	+ + −	$+1$
426.2.a.e	2	$\mathbb{Q}(\sqrt{17})$	$2q - 2q^{2} + 2q^{3} + 2q^{4} - 3q^{5} - 2q^{6} + 5q^{7} + O(q^{8})$	+ − +	$+1$
426.2.a.f	3	degree 3	$3q + 3q^{2} - 3q^{3} + 3q^{4} + 4q^{5} - 3q^{6} + 2q^{7} + O(q^{8})$	− + +	$+1$
426.2.a.g	3	degree 3	$3q + 3q^{2} + 3q^{3} + 3q^{4} + q^{5} + 3q^{6} - q^{7} + O(q^{8})$	− − −	$+1$

Hecke characteristic polynomials

The eigenvalue of $T = T_{5} + 3T_{7}$ 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 $T$
426.2.a.a	$x - 4$
426.2.a.b	$x$
426.2.a.c	$x - 10$
426.2.a.d	$x^{2} + 4x - 238$
426.2.a.e	$x^{2} - 12x - 32$
426.2.a.f	$x^{3} - 10x^{2} - 18x + 268$
426.2.a.g	$x^{3} + 2x^{2} - 48x - 32$

Dimensions

Newforms $S_{2}^{\mathrm{new}}(\Gamma_0(426))$	13
Old forms	56
Cusp forms $S_{2}(\Gamma_0(426))$	69
Eisenstein series $E_{2}(\Gamma_0(426))$	7
Modular forms $M_{2}(\Gamma_0(426))$	76

Decomposition of the old subspace

$S_{2}^{\mathrm{old}}(\Gamma_0(426)) =$ $S_{2}^{\mathrm{new}}(\Gamma_0(71))^{\oplus 4}$ $\oplus$ $S_{2}^{\mathrm{new}}(\Gamma_0(142))^{\oplus 2}$ $\oplus$ $S_{2}^{\mathrm{new}}(\Gamma_0(213))^{\oplus 2}$

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.223 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, 3, 6, 71, 142, 213, 426]: [0, 1, 1, 3, 7, 20, 26, 76] (certified at ell = 2147483171)
T = [(5, 1), (7, 3)]; h of degree 13 = 1 x 13 (phi(ord eps) x dim S_k^new); 2 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(426, 2)

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

cargo run --release -p sagebrush-web --example atlas -- 426:2 1000

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