Atlas › Modular forms › Weight 2 › Level 418 › 418.2.a › 418.2.a.f

Newform orbit 418.2.a.f

Trace form

The 2 newforms in this orbit are conjugate over $\mathbb{Q}$ ; the sum of their $q$ -expansions is

$2q + 2q^{2} - q^{3} + 2q^{4} + 3q^{5} - q^{6} - 5q^{7} + 2q^{8} + 5q^{9} + 3q^{10} + 2q^{11} - q^{12} + 7q^{13} - 5q^{14} + 9q^{15} + 2q^{16} - 6q^{17} + 5q^{18} + 2q^{19} + 3q^{20} - 8q^{21} + 2q^{22} + 6q^{23} - q^{24} + O(q^{25})$

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}(\sqrt{21})$ . It is generated by the eigenvalue $\alpha$ of $T = T_{3} + 3T_{5}$ , whose minimal polynomial is

$x^{2} - 8x - 68$

Atkin–Lehner signs

$p$	$w_p$
2	$-1$
11	$-1$
19	$-1$

For $p \parallel N$ every form in the orbit has $a_p = -p^{k/2-1} w_p$ . The Fricke sign is $w_N = -1$ , so the sign of the functional equation is $(-1)^{k/2} w_N = +1$ : each L-function in the orbit has even analytic rank.

Traces of Hecke eigenvalues

$p$	2	3	5	7	11	13	17	19	23	29	31	37	41	43	47	53	59	61	67	71	73	79	83	89	97
$\operatorname{tr} a_p$	2	−1	3	−5	2	7	−6	2	6	9	−17	16	3	1	0	6	0	4	−5	−9	10	−2	−3	−18	16

$\operatorname{tr} a_n$ for every $n \le 1000$ is in the JSON.

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.318 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 label, dimension and $\operatorname{tr} a_p$ for every $p < 1000$ equal LMFDB's.

The engine's checks

dim M^+ at levels [1, 2, 11, 19, 22, 38, 209, 418]: [0, 1, 2, 2, 5, 7, 22, 64] (certified at ell = 2147482801)
T = [(3, 1), (5, 3)]; h of degree 15 = 1 x 15 (phi(ord eps) x dim S_k^new); 3 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(418, 2)[5]   # 418.2.a.f

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

cargo run --release -p sagebrush-web --example atlas -- 418:2 1000