Atlas › Modular forms › Weight 2 › Level 766 › 766.2.a › 766.2.a.b

Newform orbit 766.2.a.b

Trace form

The 4 newforms in this orbit are conjugate over $\mathbb{Q}$ ; the sum of their $q$ -expansions is

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

Coefficient field

The coefficients $a_n$ generate a number field of degree 4. It is generated by the eigenvalue $\alpha$ of $T = T_{3} + T_{5}$ , whose minimal polynomial is

$x^{4} - 10x^{3} + 28x^{2} - 16x - 4$

Atkin–Lehner signs

$p$	$w_p$
2	$-1$
383	$+1$

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
$\operatorname{tr} a_p$	4	8	2	4	6	−4	−4	0	−4	12	−4	−4	4	−4	−12	2	4	2	−8	20	−24	12	−2	12	−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 0.243 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, 383, 766]: [0, 1, 33, 98] (certified at ell = 2147476031)
T = [(3, 1), (5, 1)]; h of degree 31 = 1 x 31 (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(766, 2)[1]   # 766.2.a.b

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

cargo run --release -p sagebrush-web --example atlas -- 766:2 1000