Properties

Label 855.2.b.c
Level $855$
Weight $2$
Character orbit 855.b
Analytic conductor $6.827$
Analytic rank $0$
Dimension $8$
CM discriminant -19
Inner twists $8$

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Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [855,2,Mod(854,855)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(855, base_ring=CyclotomicField(2))
 
chi = DirichletCharacter(H, H._module([1, 1, 1]))
 
N = Newforms(chi, 2, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("855.854");
 
S:= CuspForms(chi, 2);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 855 = 3^{2} \cdot 5 \cdot 19 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 855.b (of order \(2\), degree \(1\), minimal)

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: no
Analytic conductor: \(6.82720937282\)
Analytic rank: \(0\)
Dimension: \(8\)
Coefficient field: 8.0.8540717056.1
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{8} + 31x^{4} + 625 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{11}]\)
Coefficient ring index: \( 3^{4} \)
Twist minimal: yes
Sato-Tate group: $\mathrm{U}(1)[D_{2}]$

$q$-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 \(1,\beta_1,\ldots,\beta_{7}\) for the coefficient ring described below. We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + 2 q^{4} + \beta_{6} q^{5} + ( - \beta_{3} - \beta_{2}) q^{7}+O(q^{10}) \) Copy content Toggle raw display \( q + 2 q^{4} + \beta_{6} q^{5} + ( - \beta_{3} - \beta_{2}) q^{7} + (\beta_{7} - \beta_{6} - \beta_{4} - \beta_1) q^{11} + 4 q^{16} + (\beta_{7} + \beta_{6} + \beta_{4} - \beta_1) q^{17} + ( - \beta_{3} + \beta_{2}) q^{19} + 2 \beta_{6} q^{20} + (\beta_{7} - 2 \beta_{6} + \cdots + 2 \beta_1) q^{23}+ \cdots + ( - 3 \beta_{4} + \beta_1) q^{95}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 8 q + 16 q^{4}+O(q^{10}) \) Copy content Toggle raw display \( 8 q + 16 q^{4} + 32 q^{16} - 16 q^{49} + 28 q^{55} + 64 q^{64} + 52 q^{85}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{8} + 31x^{4} + 625 \) : Copy content Toggle raw display

\(\beta_{1}\)\(=\) \( ( \nu^{5} + 56\nu ) / 45 \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( ( -\nu^{6} + 19\nu^{2} ) / 75 \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( ( 2\nu^{6} + 37\nu^{2} ) / 75 \) Copy content Toggle raw display
\(\beta_{4}\)\(=\) \( ( -\nu^{5} - 11\nu ) / 15 \) Copy content Toggle raw display
\(\beta_{5}\)\(=\) \( ( \nu^{4} + 17 ) / 3 \) Copy content Toggle raw display
\(\beta_{6}\)\(=\) \( ( \nu^{7} + 56\nu^{3} ) / 225 \) Copy content Toggle raw display
\(\beta_{7}\)\(=\) \( ( -4\nu^{7} + \nu^{3} ) / 375 \) Copy content Toggle raw display
\(\nu\)\(=\) \( ( \beta_{4} + 3\beta_1 ) / 3 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( \beta_{3} + 2\beta_{2} \) Copy content Toggle raw display
\(\nu^{3}\)\(=\) \( ( 5\beta_{7} + 12\beta_{6} ) / 3 \) Copy content Toggle raw display
\(\nu^{4}\)\(=\) \( 3\beta_{5} - 17 \) Copy content Toggle raw display
\(\nu^{5}\)\(=\) \( ( -56\beta_{4} - 33\beta_1 ) / 3 \) Copy content Toggle raw display
\(\nu^{6}\)\(=\) \( 19\beta_{3} - 37\beta_{2} \) Copy content Toggle raw display
\(\nu^{7}\)\(=\) \( ( -280\beta_{7} + 3\beta_{6} ) / 3 \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/855\mathbb{Z}\right)^\times\).

\(n\) \(172\) \(191\) \(496\)
\(\chi(n)\) \(-1\) \(-1\) \(-1\)

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
854.1
1.18755 1.89466i
1.18755 + 1.89466i
1.89466 1.18755i
1.89466 + 1.18755i
−1.89466 1.18755i
−1.89466 + 1.18755i
−1.18755 1.89466i
−1.18755 + 1.89466i
0 0 2.00000 −1.89466 1.18755i 0 3.00000i 0 0 0
854.2 0 0 2.00000 −1.89466 + 1.18755i 0 3.00000i 0 0 0
854.3 0 0 2.00000 −1.18755 1.89466i 0 3.00000i 0 0 0
854.4 0 0 2.00000 −1.18755 + 1.89466i 0 3.00000i 0 0 0
854.5 0 0 2.00000 1.18755 1.89466i 0 3.00000i 0 0 0
854.6 0 0 2.00000 1.18755 + 1.89466i 0 3.00000i 0 0 0
854.7 0 0 2.00000 1.89466 1.18755i 0 3.00000i 0 0 0
854.8 0 0 2.00000 1.89466 + 1.18755i 0 3.00000i 0 0 0
\(n\): e.g. 2-40 or 990-1000
Embeddings: e.g. 1-3 or 854.8
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
19.b odd 2 1 CM by \(\Q(\sqrt{-19}) \)
3.b odd 2 1 inner
5.b even 2 1 inner
15.d odd 2 1 inner
57.d even 2 1 inner
95.d odd 2 1 inner
285.b even 2 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 855.2.b.c 8
3.b odd 2 1 inner 855.2.b.c 8
5.b even 2 1 inner 855.2.b.c 8
15.d odd 2 1 inner 855.2.b.c 8
19.b odd 2 1 CM 855.2.b.c 8
57.d even 2 1 inner 855.2.b.c 8
95.d odd 2 1 inner 855.2.b.c 8
285.b even 2 1 inner 855.2.b.c 8
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
855.2.b.c 8 1.a even 1 1 trivial
855.2.b.c 8 3.b odd 2 1 inner
855.2.b.c 8 5.b even 2 1 inner
855.2.b.c 8 15.d odd 2 1 inner
855.2.b.c 8 19.b odd 2 1 CM
855.2.b.c 8 57.d even 2 1 inner
855.2.b.c 8 95.d odd 2 1 inner
855.2.b.c 8 285.b even 2 1 inner

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{2}^{\mathrm{new}}(855, [\chi])\):

\( T_{2} \) Copy content Toggle raw display
\( T_{29} \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{8} \) Copy content Toggle raw display
$3$ \( T^{8} \) Copy content Toggle raw display
$5$ \( T^{8} + 31T^{4} + 625 \) Copy content Toggle raw display
$7$ \( (T^{2} + 9)^{4} \) Copy content Toggle raw display
$11$ \( (T^{4} + 44 T^{2} + 9)^{2} \) Copy content Toggle raw display
$13$ \( T^{8} \) Copy content Toggle raw display
$17$ \( (T^{4} - 68 T^{2} + 225)^{2} \) Copy content Toggle raw display
$19$ \( (T^{2} - 19)^{4} \) Copy content Toggle raw display
$23$ \( (T^{4} - 92 T^{2} + 900)^{2} \) Copy content Toggle raw display
$29$ \( T^{8} \) Copy content Toggle raw display
$31$ \( T^{8} \) Copy content Toggle raw display
$37$ \( T^{8} \) Copy content Toggle raw display
$41$ \( T^{8} \) Copy content Toggle raw display
$43$ \( (T^{2} + 171)^{4} \) Copy content Toggle raw display
$47$ \( (T^{4} - 188 T^{2} + 5625)^{2} \) Copy content Toggle raw display
$53$ \( T^{8} \) Copy content Toggle raw display
$59$ \( T^{8} \) Copy content Toggle raw display
$61$ \( (T^{2} - 19)^{4} \) Copy content Toggle raw display
$67$ \( T^{8} \) Copy content Toggle raw display
$71$ \( T^{8} \) Copy content Toggle raw display
$73$ \( (T^{2} + 171)^{4} \) Copy content Toggle raw display
$79$ \( T^{8} \) Copy content Toggle raw display
$83$ \( (T^{4} - 332 T^{2} + 8100)^{2} \) Copy content Toggle raw display
$89$ \( T^{8} \) Copy content Toggle raw display
$97$ \( T^{8} \) Copy content Toggle raw display
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