Newspace parameters
comment: Compute space of new eigenforms
[N,k,chi] = [4,18,Mod(1,4)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(4, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0]))
N = Newforms(chi, 18, names="a")
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("4.1");
S:= CuspForms(chi, 18);
N := Newforms(S);
| Level: | \( N \) | \(=\) | \( 4 = 2^{2} \) |
| Weight: | \( k \) | \(=\) | \( 18 \) |
| Character orbit: | \([\chi]\) | \(=\) | 4.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: | \(7.32888349378\) |
| Analytic rank: | \(0\) |
| Dimension: | \(2\) |
| Coefficient field: | \(\Q(\sqrt{9361}) \) |
|
comment: defining polynomial
gp: f.mod \\ as an extension of the character field
|
|
| Defining polynomial: |
\( x^{2} - x - 2340 \)
|
| Coefficient ring: | \(\Z[a_1, a_2, a_3]\) |
| Coefficient ring index: | \( 2^{7}\cdot 3 \) |
| 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 \(\beta = 192\sqrt{9361}\). 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 | −21516.4 | 0 | 970774. | 0 | 1.64068e6 | 0 | 3.33817e8 | 0 | ||||||||||||||||||||||||
| 1.2 | 0 | 15636.4 | 0 | −366730. | 0 | 2.37095e7 | 0 | 1.15358e8 | 0 | |||||||||||||||||||||||||
Atkin-Lehner signs
| \( p \) | Sign |
|---|---|
| \(2\) | \(-1\) |
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 | 4.18.a.a | ✓ | 2 |
| 3.b | odd | 2 | 1 | 36.18.a.d | 2 | ||
| 4.b | odd | 2 | 1 | 16.18.a.e | 2 | ||
| 5.b | even | 2 | 1 | 100.18.a.b | 2 | ||
| 5.c | odd | 4 | 2 | 100.18.c.a | 4 | ||
| 8.b | even | 2 | 1 | 64.18.a.l | 2 | ||
| 8.d | odd | 2 | 1 | 64.18.a.g | 2 | ||
| By twisted newform orbit | |||||||
|---|---|---|---|---|---|---|---|
| Twist | Min | Dim | Char | Parity | Ord | Mult | Type |
| 4.18.a.a | ✓ | 2 | 1.a | even | 1 | 1 | trivial |
| 16.18.a.e | 2 | 4.b | odd | 2 | 1 | ||
| 36.18.a.d | 2 | 3.b | odd | 2 | 1 | ||
| 64.18.a.g | 2 | 8.d | odd | 2 | 1 | ||
| 64.18.a.l | 2 | 8.b | even | 2 | 1 | ||
| 100.18.a.b | 2 | 5.b | even | 2 | 1 | ||
| 100.18.c.a | 4 | 5.c | odd | 4 | 2 | ||
Hecke kernels
This newform subspace is the entire newspace \(S_{18}^{\mathrm{new}}(\Gamma_0(4))\).
Hecke characteristic polynomials
| $p$ | $F_p(T)$ |
|---|---|
| $2$ |
\( T^{2} \)
|
| $3$ |
\( T^{2} + 5880 T - 336440304 \)
|
| $5$ |
\( T^{2} + \cdots - 356011451100 \)
|
| $7$ |
\( T^{2} + \cdots + 38899628654656 \)
|
| $11$ |
\( T^{2} + \cdots - 10\!\cdots\!00 \)
|
| $13$ |
\( T^{2} + \cdots - 87\!\cdots\!44 \)
|
| $17$ |
\( T^{2} + \cdots + 17\!\cdots\!04 \)
|
| $19$ |
\( T^{2} + \cdots - 26\!\cdots\!44 \)
|
| $23$ |
\( T^{2} + \cdots - 64\!\cdots\!36 \)
|
| $29$ |
\( T^{2} + \cdots - 50\!\cdots\!24 \)
|
| $31$ |
\( T^{2} + \cdots - 57\!\cdots\!04 \)
|
| $37$ |
\( T^{2} + \cdots + 25\!\cdots\!76 \)
|
| $41$ |
\( T^{2} + \cdots - 12\!\cdots\!44 \)
|
| $43$ |
\( T^{2} + \cdots + 22\!\cdots\!00 \)
|
| $47$ |
\( T^{2} + \cdots + 42\!\cdots\!44 \)
|
| $53$ |
\( T^{2} + \cdots + 85\!\cdots\!24 \)
|
| $59$ |
\( T^{2} + \cdots + 19\!\cdots\!44 \)
|
| $61$ |
\( T^{2} + \cdots - 45\!\cdots\!76 \)
|
| $67$ |
\( T^{2} + \cdots - 39\!\cdots\!84 \)
|
| $71$ |
\( T^{2} + \cdots - 37\!\cdots\!56 \)
|
| $73$ |
\( T^{2} + \cdots + 40\!\cdots\!76 \)
|
| $79$ |
\( T^{2} + \cdots + 11\!\cdots\!04 \)
|
| $83$ |
\( T^{2} + \cdots + 46\!\cdots\!84 \)
|
| $89$ |
\( T^{2} + \cdots + 65\!\cdots\!36 \)
|
| $97$ |
\( T^{2} + \cdots - 28\!\cdots\!64 \)
|
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