Atlas › Modular forms › Weight 8 › Level 28 › 28.8.a › 28.8.a.b

Newform orbit 28.8.a.b

Trace form

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

$2q + 14q^{3} - 294q^{5} - 686q^{7} - 2258q^{9} - 3492q^{11} - 16170q^{13} - 24256q^{15} - 29232q^{17} - 3206q^{19} - 4802q^{21} - 9360q^{23} + O(q^{25})$

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}(\sqrt{1009})$ . It is generated by the eigenvalue $\alpha$ of $T = T_{3} + T_{5}$ , whose minimal polynomial is

$x^{2} + 280x - 81300$

Atkin–Lehner signs

$p$	$w_p$
2	— ( $2^2 \mid 28$ )
7	$+1$

For $p \parallel N$ every form in the orbit has $a_p = -p^{k/2-1} w_p$ .

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
$\operatorname{tr} a_p$	0	14	−294	−686	−3492	−16170	−29232	−3206	−9360	184704	165060	286144	−116760	−294428	−1014132	−1396452	−2729286	2466954	225176	1530312	1143548	7951176	−18487854	−4652508	−26702368

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

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.271 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 engine's checks

dim M^+ at levels [1, 2, 4, 7, 14, 28]: [1, 3, 5, 5, 16, 31] (certified at ell = 2147483647)
T = [(3, 1), (5, 1)]; h of degree 4 = 1 x 4 (phi(ord eps) x dim S_k^new); 2 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(28, 8)[1]   # 28.8.a.b

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

cargo run --release -p sagebrush-web --example atlas -- 28:8 1000