Atlas › Modular forms › Weight 2 › Level 818 › 818.2.a › 818.2.a.b

Newform orbit 818.2.a.b

Trace form

The 7 newforms in this orbit are conjugate over $\mathbb{Q}$ ; the sum of their $q$ -expansions is

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

Coefficient field

The coefficients $a_n$ generate a number field of degree 7. It is generated by the eigenvalue $\alpha$ of $T = T_{3} + T_{5}$ , whose minimal polynomial is

$x^{7} + 3x^{6} - 15x^{5} - 19x^{4} + 71x^{3} + 14x^{2} - 108x + 52$

Atkin–Lehner signs

$p$	$w_p$
2	$+1$
409	$+1$

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 odd 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
$\operatorname{tr} a_p$	−7	−4	1	−11	3	−12	−5	−1	−12	4	−5	−12	12	−30	−16	0	5	−8	−43	−9	−20	−27	−16	25	−11

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

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.246 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, 409, 818]: [0, 1, 34, 104] (certified at ell = 2147477809)
T = [(3, 1), (5, 1)]; h of degree 35 = 1 x 35 (phi(ord eps) x dim S_k^new); 4 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(818, 2)[1]   # 818.2.a.b

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

cargo run --release -p sagebrush-web --example atlas -- 818:2 1000