Atlas › Modular forms › Weight 4 › Level 15 › 15.4.a › 15.4.a.b

Newform orbit 15.4.a.b

$q$ -expansion

$q + 3q^{2} - 3q^{3} + q^{4} - 5q^{5} - 9q^{6} + 20q^{7} - 21q^{8} + 9q^{9} - 15q^{10} - 24q^{11} - 3q^{12} + 74q^{13} + 60q^{14} + 15q^{15} - 71q^{16} + 54q^{17} + 27q^{18} - 124q^{19} - 5q^{20} - 60q^{21} - 72q^{22} - 120q^{23} + 63q^{24} + O(q^{25})$

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}$ . The eigenvalue of $T = T_{2} + T_{7}$ is a root of

$x - 23$

Atkin–Lehner signs

$p$	$w_p$
3	$+1$
5	$+1$

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
$\operatorname{tr} a_p$	3	−3	−5	20	−24	74	54	−124	−120	−78	200	−70	330	92	−24	450	24	−322	−196	−288	−430	−520	156	1026	−286

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

Sato–Tate

The normalized $a_p / 2p^{3/2}$ for the primes $p < 1000$ not dividing 15, against the semicircle $\tfrac{2}{\pi}\sqrt{1 - x^2}$ :

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.097 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, 3, 5, 15]: [1, 2, 3, 8] (certified at ell = 2147483629)
T = [(2, 1), (7, 1)]; h of degree 2 = 1 x 2 (phi(ord eps) x dim S_k^new); 1 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(15, 4)[1]   # 15.4.a.b

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

cargo run --release -p sagebrush-web --example atlas -- 15:4 1000