Atlas › Modular forms › Weight 2 › Level 340 › 340.2.a › 340.2.a.a

Newform orbit 340.2.a.a

$q$ -expansion

$q - q^{5} - 4q^{7} - 3q^{9} + 2q^{11} - 6q^{13} + q^{17} + O(q^{25})$

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}$ . The eigenvalue of $T = T_{3} + 3T_{7}$ is a root of

$x + 12$

Atkin–Lehner signs

$p$	$w_p$
2	— ( $2^2 \mid 340$ )
5	$+1$
17	$-1$

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

Elliptic curve

By modularity this newform is the one attached to the isogeny class 340.a (Cremona's 340a). Its optimal curve 340a1 is

$y^2 = x^3 - 28x + 57$

of rank 1 with torsion of order 2. Its $a_p$ , computed by Sagebrush's point-counting engine, equal the newform's for every prime $p < 1000$ .

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	0	−1	−4	2	−6	1	0	0	−6	6	−2	−6	6	−10	−6	0	10	−2	6	6	6	6	−18	−14

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

Sato–Tate

The normalized $a_p / 2p^{1/2}$ for the primes $p < 1000$ not dividing 340, against the semicircle $\tfrac{2}{\pi}\sqrt{1 - x^2}$ :

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.207 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, 4, 5, 10, 17, 20, 34, 68, 85, 170, 340]: [0, 1, 2, 1, 3, 2, 6, 6, 12, 10, 30, 60] (certified at ell = 2147483489)
T = [(3, 1), (7, 3)]; h of degree 4 = 1 x 4 (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(340, 2)[0]   # 340.2.a.a

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

cargo run --release -p sagebrush-web --example atlas -- 340:2 1000