Atlas › Modular forms › Weight 2 › Level 655 › 655.2.a › 655.2.a.c

Newform orbit 655.2.a.c

Trace form

The 8 newforms in this orbit are conjugate over $\mathbb{Q}$ ; the sum of their $q$ -expansions is

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

Coefficient field

The coefficients $a_n$ generate a number field of degree 8. It is generated by the eigenvalue $\alpha$ of $T = T_{2} + T_{3}$ , whose minimal polynomial is

$x^{8} + 4x^{7} - 7x^{6} - 31x^{5} + 26x^{4} + 67x^{3} - 61x^{2} + 5$

Atkin–Lehner signs

$p$	$w_p$
5	$+1$
131	$+1$

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
$\operatorname{tr} a_p$	−3	−1	−8	0	−8	2	−15	−13	−4	−26	−19	11	−27	10	−11	−1	−20	−8	6	−28	−15	−4	−19	−61	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 0.219 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, 5, 131, 655]: [0, 1, 12, 68] (certified at ell = 2147482481)
T = [(2, 1), (3, 1)]; h of degree 43 = 1 x 43 (phi(ord eps) x dim S_k^new); 5 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(655, 2)[2]   # 655.2.a.c

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

cargo run --release -p sagebrush-web --example atlas -- 655:2 1000