Newspace parameters
comment: Compute space of new eigenforms
[N,k,chi] = [255,2,Mod(1,255)]
mf = mfinit([N,k,chi],0)
lf = mfeigenbasis(mf)
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(255, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0, 0, 0]))
N = Newforms(chi, 2, names="a")
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("255.1");
S:= CuspForms(chi, 2);
N := Newforms(S);
| Level: | \( N \) | \(=\) | \( 255 = 3 \cdot 5 \cdot 17 \) |
| Weight: | \( k \) | \(=\) | \( 2 \) |
| Character orbit: | \([\chi]\) | \(=\) | 255.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: | \(2.03618525154\) |
| Analytic rank: | \(0\) |
| Dimension: | \(4\) |
| Coefficient field: | 4.4.13768.1 |
|
comment: defining polynomial
gp: f.mod \\ as an extension of the character field
|
|
| Defining polynomial: |
\( x^{4} - x^{3} - 5x^{2} + 2x + 2 \)
|
| Coefficient ring: | \(\Z[a_1, a_2]\) |
| Coefficient ring index: | \( 2 \) |
| 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 a basis \(1,\beta_1,\beta_2,\beta_3\) for the coefficient ring described below. We also show the integral \(q\)-expansion of the trace form.
Basis of coefficient ring in terms of a root \(\nu\) of
\( x^{4} - x^{3} - 5x^{2} + 2x + 2 \)
:
| \(\beta_{1}\) | \(=\) |
\( \nu^{2} - 3 \)
|
| \(\beta_{2}\) | \(=\) |
\( -\nu^{2} + 2\nu + 2 \)
|
| \(\beta_{3}\) | \(=\) |
\( \nu^{3} - \nu^{2} - 4\nu + 1 \)
|
| \(\nu\) | \(=\) |
\( ( \beta_{2} + \beta _1 + 1 ) / 2 \)
|
| \(\nu^{2}\) | \(=\) |
\( \beta _1 + 3 \)
|
| \(\nu^{3}\) | \(=\) |
\( \beta_{3} + 2\beta_{2} + 3\beta _1 + 4 \)
|
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 |
|
−2.60015 | 1.00000 | 4.76079 | −1.00000 | −2.60015 | 2.81754 | −7.17848 | 1.00000 | 2.60015 | ||||||||||||||||||||||||||||||
| 1.2 | −0.749250 | 1.00000 | −1.43862 | −1.00000 | −0.749250 | 1.11299 | 2.57639 | 1.00000 | 0.749250 | |||||||||||||||||||||||||||||||
| 1.3 | 1.84366 | 1.00000 | 1.39907 | −1.00000 | 1.84366 | 4.55250 | −1.10791 | 1.00000 | −1.84366 | |||||||||||||||||||||||||||||||
| 1.4 | 2.50575 | 1.00000 | 4.27876 | −1.00000 | 2.50575 | −4.48302 | 5.71000 | 1.00000 | −2.50575 | |||||||||||||||||||||||||||||||
Atkin-Lehner signs
| \( p \) | Sign |
|---|---|
| \(3\) | \(-1\) |
| \(5\) | \(1\) |
| \(17\) | \(1\) |
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 | 255.2.a.d | ✓ | 4 |
| 3.b | odd | 2 | 1 | 765.2.a.m | 4 | ||
| 4.b | odd | 2 | 1 | 4080.2.a.bt | 4 | ||
| 5.b | even | 2 | 1 | 1275.2.a.t | 4 | ||
| 5.c | odd | 4 | 2 | 1275.2.b.k | 8 | ||
| 15.d | odd | 2 | 1 | 3825.2.a.bi | 4 | ||
| 17.b | even | 2 | 1 | 4335.2.a.z | 4 | ||
| By twisted newform orbit | |||||||
|---|---|---|---|---|---|---|---|
| Twist | Min | Dim | Char | Parity | Ord | Mult | Type |
| 255.2.a.d | ✓ | 4 | 1.a | even | 1 | 1 | trivial |
| 765.2.a.m | 4 | 3.b | odd | 2 | 1 | ||
| 1275.2.a.t | 4 | 5.b | even | 2 | 1 | ||
| 1275.2.b.k | 8 | 5.c | odd | 4 | 2 | ||
| 3825.2.a.bi | 4 | 15.d | odd | 2 | 1 | ||
| 4080.2.a.bt | 4 | 4.b | odd | 2 | 1 | ||
| 4335.2.a.z | 4 | 17.b | even | 2 | 1 | ||
Hecke kernels
This newform subspace can be constructed as the kernel of the linear operator
\( T_{2}^{4} - T_{2}^{3} - 8T_{2}^{2} + 7T_{2} + 9 \)
acting on \(S_{2}^{\mathrm{new}}(\Gamma_0(255))\).
Hecke characteristic polynomials
| $p$ | $F_p(T)$ |
|---|---|
| $2$ |
\( T^{4} - T^{3} - 8 T^{2} + \cdots + 9 \)
|
| $3$ |
\( (T - 1)^{4} \)
|
| $5$ |
\( (T + 1)^{4} \)
|
| $7$ |
\( T^{4} - 4 T^{3} + \cdots - 64 \)
|
| $11$ |
\( T^{4} - 2 T^{3} + \cdots - 96 \)
|
| $13$ |
\( T^{4} + 2 T^{3} + \cdots + 208 \)
|
| $17$ |
\( (T + 1)^{4} \)
|
| $19$ |
\( T^{4} - 12 T^{3} + \cdots - 16 \)
|
| $23$ |
\( T^{4} - 2 T^{3} + \cdots + 2304 \)
|
| $29$ |
\( T^{4} - 4 T^{3} + \cdots + 12 \)
|
| $31$ |
\( T^{4} - 6 T^{3} + \cdots + 128 \)
|
| $37$ |
\( T^{4} + 2 T^{3} + \cdots + 1124 \)
|
| $41$ |
\( T^{4} - 109 T^{2} + \cdots + 1308 \)
|
| $43$ |
\( T^{4} - 4 T^{3} + \cdots + 512 \)
|
| $47$ |
\( T^{4} + 2 T^{3} + \cdots - 96 \)
|
| $53$ |
\( T^{4} - 109 T^{2} + \cdots + 1308 \)
|
| $59$ |
\( T^{4} + 10 T^{3} + \cdots - 192 \)
|
| $61$ |
\( T^{4} + 2 T^{3} + \cdots + 208 \)
|
| $67$ |
\( T^{4} - 22 T^{3} + \cdots - 13184 \)
|
| $71$ |
\( T^{4} + 20 T^{3} + \cdots - 768 \)
|
| $73$ |
\( T^{4} + 10 T^{3} + \cdots - 108 \)
|
| $79$ |
\( T^{4} - 84 T^{2} + \cdots - 128 \)
|
| $83$ |
\( T^{4} + 20 T^{3} + \cdots - 768 \)
|
| $89$ |
\( T^{4} - 10 T^{3} + \cdots + 3888 \)
|
| $97$ |
\( T^{4} - 12 T^{3} + \cdots + 944 \)
|
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