Atlas › Modular forms › Weight 2 › Level 998 › 998.2.a › 998.2.a.b

Newform orbit 998.2.a.b

Trace form

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

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

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}(\sqrt{5})$ . It is generated by the eigenvalue $\alpha$ of $T = T_{3} + 3T_{5} + 5T_{7} + 7T_{11}$ , whose minimal polynomial is

$x^{2} - 11x - 121$

Atkin–Lehner signs

$p$	$w_p$
2	$+1$
499	$+1$

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
$\operatorname{tr} a_p$	−2	0	0	−2	3	−10	−9	7	−3	6	−3	−9	15	−10	−18	−6	9	−4	3	−9	2	−20	18	6	6

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

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.502 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, 499, 998]: [0, 1, 42, 127] (certified at ell = 2147475601)
T = [(3, 1), (5, 3), (7, 5), (11, 7)]; h of degree 42 = 1 x 42 (phi(ord eps) x dim S_k^new); 10 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(998, 2)[1]   # 998.2.a.b

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

cargo run --release -p sagebrush-web --example atlas -- 998:2 1000