Newspace parameters
comment: Compute space of new eigenforms
[N,k,chi] = [841,2,Mod(1,841)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(841, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0]))
N = Newforms(chi, 2, names="a")
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("841.1");
S:= CuspForms(chi, 2);
N := Newforms(S);
| Level: | \( N \) | \(=\) | \( 841 = 29^{2} \) |
| Weight: | \( k \) | \(=\) | \( 2 \) |
| Character orbit: | \([\chi]\) | \(=\) | 841.a (trivial) |
Newform invariants
comment: select newform
sage: f = N[0] # Warning: the index may be different
gp: f = lf[1] \\ Warning: the index may be different
| Self dual: | yes |
| Analytic conductor: | \(6.71541880999\) |
| Analytic rank: | \(0\) |
| Dimension: | \(2\) |
| Coefficient field: | \(\Q(\sqrt{5}) \) |
|
comment: defining polynomial
gp: f.mod \\ as an extension of the character field
|
|
| Defining polynomial: |
\( x^{2} - x - 1 \)
|
| Coefficient ring: | \(\Z[a_1, a_2]\) |
| Coefficient ring index: | \( 1 \) |
| Twist minimal: | yes |
| Fricke sign: | \(-1\) |
| Sato-Tate group: | $\mathrm{SU}(2)$ |
$q$-expansion
comment: q-expansion
sage: f.q_expansion() # note that sage often uses an isomorphic number field
gp: mfcoefs(f, 20)
Coefficients of the \(q\)-expansion are expressed in terms of \(\beta = \frac{1}{2}(1 + \sqrt{5})\). We also show the integral \(q\)-expansion of the trace form.
Embeddings
For each embedding \(\iota_m\) of the coefficient field, the values \(\iota_m(a_n)\) are shown below.
For more information on an embedded modular form you can click on its label.
comment: embeddings in the coefficient field
gp: mfembed(f)
| Label | \(\iota_m(\nu)\) | \( a_{2} \) | \( a_{3} \) | \( a_{4} \) | \( a_{5} \) | \( a_{6} \) | \( a_{7} \) | \( a_{8} \) | \( a_{9} \) | \( a_{10} \) | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.1 |
|
−0.618034 | 0.618034 | −1.61803 | 3.85410 | −0.381966 | −2.23607 | 2.23607 | −2.61803 | −2.38197 | ||||||||||||||||||||||||
| 1.2 | 1.61803 | −1.61803 | 0.618034 | −2.85410 | −2.61803 | 2.23607 | −2.23607 | −0.381966 | −4.61803 | |||||||||||||||||||||||||
Atkin-Lehner signs
| \( p \) | Sign |
|---|---|
| \(29\) | \( -1 \) |
Inner twists
This newform does not admit any (nontrivial) inner twists.
Twists
| By twisting character orbit | |||||||
|---|---|---|---|---|---|---|---|
| Char | Parity | Ord | Mult | Type | Twist | Min | Dim |
| 1.a | even | 1 | 1 | trivial | 841.2.a.c | yes | 2 |
| 3.b | odd | 2 | 1 | 7569.2.a.d | 2 | ||
| 29.b | even | 2 | 1 | 841.2.a.a | ✓ | 2 | |
| 29.c | odd | 4 | 2 | 841.2.b.b | 4 | ||
| 29.d | even | 7 | 6 | 841.2.d.g | 12 | ||
| 29.e | even | 14 | 6 | 841.2.d.i | 12 | ||
| 29.f | odd | 28 | 12 | 841.2.e.j | 24 | ||
| 87.d | odd | 2 | 1 | 7569.2.a.l | 2 | ||
| By twisted newform orbit | |||||||
|---|---|---|---|---|---|---|---|
| Twist | Min | Dim | Char | Parity | Ord | Mult | Type |
| 841.2.a.a | ✓ | 2 | 29.b | even | 2 | 1 | |
| 841.2.a.c | yes | 2 | 1.a | even | 1 | 1 | trivial |
| 841.2.b.b | 4 | 29.c | odd | 4 | 2 | ||
| 841.2.d.g | 12 | 29.d | even | 7 | 6 | ||
| 841.2.d.i | 12 | 29.e | even | 14 | 6 | ||
| 841.2.e.j | 24 | 29.f | odd | 28 | 12 | ||
| 7569.2.a.d | 2 | 3.b | odd | 2 | 1 | ||
| 7569.2.a.l | 2 | 87.d | odd | 2 | 1 | ||
Hecke kernels
This newform subspace can be constructed as the kernel of the linear operator
\( T_{2}^{2} - T_{2} - 1 \)
acting on \(S_{2}^{\mathrm{new}}(\Gamma_0(841))\).
Hecke characteristic polynomials
| $p$ | $F_p(T)$ |
|---|---|
| $2$ |
\( T^{2} - T - 1 \)
|
| $3$ |
\( T^{2} + T - 1 \)
|
| $5$ |
\( T^{2} - T - 11 \)
|
| $7$ |
\( T^{2} - 5 \)
|
| $11$ |
\( T^{2} - 5T + 5 \)
|
| $13$ |
\( T^{2} - 4T - 1 \)
|
| $17$ |
\( T^{2} - 11T + 29 \)
|
| $19$ |
\( T^{2} - 3T - 9 \)
|
| $23$ |
\( T^{2} - 2T - 4 \)
|
| $29$ |
\( T^{2} \)
|
| $31$ |
\( T^{2} - 9T - 11 \)
|
| $37$ |
\( T^{2} - 4T - 41 \)
|
| $41$ |
\( T^{2} + T - 11 \)
|
| $43$ |
\( T^{2} - 10T + 20 \)
|
| $47$ |
\( (T - 7)^{2} \)
|
| $53$ |
\( (T + 2)^{2} \)
|
| $59$ |
\( T^{2} - T - 31 \)
|
| $61$ |
\( T^{2} + T - 1 \)
|
| $67$ |
\( T^{2} + 12T + 16 \)
|
| $71$ |
\( T^{2} - 12T + 16 \)
|
| $73$ |
\( T^{2} - 14T + 4 \)
|
| $79$ |
\( T^{2} - T - 31 \)
|
| $83$ |
\( T^{2} + 2T - 79 \)
|
| $89$ |
\( T^{2} - 4T - 41 \)
|
| $97$ |
\( T^{2} - 13T - 59 \)
|
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