Properties

Label 855.2.be.c
Level $855$
Weight $2$
Character orbit 855.be
Analytic conductor $6.827$
Analytic rank $0$
Dimension $8$
CM discriminant -15
Inner twists $8$

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Show commands: Magma / PariGP / SageMath

Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [855,2,Mod(64,855)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(855, base_ring=CyclotomicField(6))
 
chi = DirichletCharacter(H, H._module([0, 3, 2]))
 
N = Newforms(chi, 2, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("855.64");
 
S:= CuspForms(chi, 2);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 855 = 3^{2} \cdot 5 \cdot 19 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 855.be (of order \(6\), degree \(2\), 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: \(8\)
Relative dimension: \(4\) over \(\Q(\zeta_{6})\)
Coefficient field: 8.0.12960000.1
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{8} - 3x^{6} + 8x^{4} - 3x^{2} + 1 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{19}]\)
Coefficient ring index: \( 3^{2} \)
Twist minimal: yes
Sato-Tate group: $\mathrm{U}(1)[D_{6}]$

$q$-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.

\(f(q)\) \(=\) \( q + ( - \beta_{7} + \beta_{5} + \beta_{4}) q^{2} + (2 \beta_{6} - 2 \beta_{2} + \beta_1 - 1) q^{4} + ( - \beta_{7} + \beta_{5} + \beta_{3}) q^{5} + ( - \beta_{7} + 2 \beta_{5} + \cdots - 2 \beta_{3}) q^{8}+O(q^{10}) \) Copy content Toggle raw display \( q + ( - \beta_{7} + \beta_{5} + \beta_{4}) q^{2} + (2 \beta_{6} - 2 \beta_{2} + \beta_1 - 1) q^{4} + ( - \beta_{7} + \beta_{5} + \beta_{3}) q^{5} + ( - \beta_{7} + 2 \beta_{5} + \cdots - 2 \beta_{3}) q^{8}+ \cdots + ( - 7 \beta_{7} + 7 \beta_{5} + 7 \beta_{4}) q^{98}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 8 q + 6 q^{4}+O(q^{10}) \) Copy content Toggle raw display \( 8 q + 6 q^{4} + 10 q^{10} - 26 q^{16} + 8 q^{19} + 20 q^{25} - 32 q^{31} - 46 q^{34} - 40 q^{40} + 80 q^{46} + 56 q^{49} - 8 q^{61} - 16 q^{64} + 24 q^{76} + 64 q^{79} - 20 q^{85} - 148 q^{94}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{8} - 3x^{6} + 8x^{4} - 3x^{2} + 1 \) : Copy content Toggle raw display

\(\beta_{1}\)\(=\) \( ( -\nu^{6} + 8\nu^{4} - 16\nu^{2} + 19 ) / 8 \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( ( -3\nu^{6} + 8\nu^{4} - 24\nu^{2} + 1 ) / 8 \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( ( -\nu^{7} + 4\nu^{5} - 12\nu^{3} + 11\nu ) / 4 \) Copy content Toggle raw display
\(\beta_{4}\)\(=\) \( ( -\nu^{7} + 2\nu^{5} - 6\nu^{3} - 3\nu ) / 2 \) Copy content Toggle raw display
\(\beta_{5}\)\(=\) \( ( -5\nu^{7} + 16\nu^{5} - 40\nu^{3} + 23\nu ) / 8 \) Copy content Toggle raw display
\(\beta_{6}\)\(=\) \( ( -7\nu^{6} + 16\nu^{4} - 40\nu^{2} - 3 ) / 8 \) Copy content Toggle raw display
\(\beta_{7}\)\(=\) \( -\nu^{7} + 3\nu^{5} - 8\nu^{3} + 2\nu \) Copy content Toggle raw display
\(\nu\)\(=\) \( ( -2\beta_{7} + 2\beta_{5} + \beta_{4} + \beta_{3} ) / 3 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( ( 2\beta_{6} - 5\beta_{2} + \beta _1 - 1 ) / 3 \) Copy content Toggle raw display
\(\nu^{3}\)\(=\) \( ( -\beta_{7} + 4\beta_{5} - \beta_{4} - 4\beta_{3} ) / 3 \) Copy content Toggle raw display
\(\nu^{4}\)\(=\) \( \beta_{6} - 3\beta_{2} + 2\beta _1 - 4 \) Copy content Toggle raw display
\(\nu^{5}\)\(=\) \( ( 11\beta_{7} - 2\beta_{5} - 13\beta_{4} - 13\beta_{3} ) / 3 \) Copy content Toggle raw display
\(\nu^{6}\)\(=\) \( ( -8\beta_{6} + 8\beta_{2} + 8\beta _1 - 23 ) / 3 \) Copy content Toggle raw display
\(\nu^{7}\)\(=\) \( ( 34\beta_{7} - 34\beta_{5} - 29\beta_{4} - 5\beta_{3} ) / 3 \) Copy content Toggle raw display

Character values

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

\(n\) \(172\) \(191\) \(496\)
\(\chi(n)\) \(-1\) \(1\) \(\beta_{2}\)

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
64.1
−1.40126 + 0.809017i
0.535233 0.309017i
−0.535233 + 0.309017i
1.40126 0.809017i
−1.40126 0.809017i
0.535233 + 0.309017i
−0.535233 0.309017i
1.40126 + 0.809017i
−2.26728 + 1.30902i 0 2.42705 4.20378i −1.93649 + 1.11803i 0 0 7.47214i 0 2.92705 5.06980i
64.2 −0.330792 + 0.190983i 0 −0.927051 + 1.60570i 1.93649 1.11803i 0 0 1.47214i 0 −0.427051 + 0.739674i
64.3 0.330792 0.190983i 0 −0.927051 + 1.60570i −1.93649 + 1.11803i 0 0 1.47214i 0 −0.427051 + 0.739674i
64.4 2.26728 1.30902i 0 2.42705 4.20378i 1.93649 1.11803i 0 0 7.47214i 0 2.92705 5.06980i
334.1 −2.26728 1.30902i 0 2.42705 + 4.20378i −1.93649 1.11803i 0 0 7.47214i 0 2.92705 + 5.06980i
334.2 −0.330792 0.190983i 0 −0.927051 1.60570i 1.93649 + 1.11803i 0 0 1.47214i 0 −0.427051 0.739674i
334.3 0.330792 + 0.190983i 0 −0.927051 1.60570i −1.93649 1.11803i 0 0 1.47214i 0 −0.427051 0.739674i
334.4 2.26728 + 1.30902i 0 2.42705 + 4.20378i 1.93649 + 1.11803i 0 0 7.47214i 0 2.92705 + 5.06980i
\(n\): e.g. 2-40 or 990-1000
Embeddings: e.g. 1-3 or 64.4
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
15.d odd 2 1 CM by \(\Q(\sqrt{-15}) \)
3.b odd 2 1 inner
5.b even 2 1 inner
19.c even 3 1 inner
57.h odd 6 1 inner
95.i even 6 1 inner
285.n odd 6 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 855.2.be.c 8
3.b odd 2 1 inner 855.2.be.c 8
5.b even 2 1 inner 855.2.be.c 8
15.d odd 2 1 CM 855.2.be.c 8
19.c even 3 1 inner 855.2.be.c 8
57.h odd 6 1 inner 855.2.be.c 8
95.i even 6 1 inner 855.2.be.c 8
285.n odd 6 1 inner 855.2.be.c 8
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
855.2.be.c 8 1.a even 1 1 trivial
855.2.be.c 8 3.b odd 2 1 inner
855.2.be.c 8 5.b even 2 1 inner
855.2.be.c 8 15.d odd 2 1 CM
855.2.be.c 8 19.c even 3 1 inner
855.2.be.c 8 57.h odd 6 1 inner
855.2.be.c 8 95.i even 6 1 inner
855.2.be.c 8 285.n odd 6 1 inner

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{2}^{8} - 7T_{2}^{6} + 48T_{2}^{4} - 7T_{2}^{2} + 1 \) acting on \(S_{2}^{\mathrm{new}}(855, [\chi])\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{8} - 7 T^{6} + \cdots + 1 \) Copy content Toggle raw display
$3$ \( T^{8} \) Copy content Toggle raw display
$5$ \( (T^{4} - 5 T^{2} + 25)^{2} \) Copy content Toggle raw display
$7$ \( T^{8} \) Copy content Toggle raw display
$11$ \( T^{8} \) Copy content Toggle raw display
$13$ \( T^{8} \) Copy content Toggle raw display
$17$ \( T^{8} - 82 T^{6} + \cdots + 923521 \) Copy content Toggle raw display
$19$ \( (T^{4} - 4 T^{3} + \cdots + 361)^{2} \) Copy content Toggle raw display
$23$ \( (T^{4} - 80 T^{2} + 6400)^{2} \) Copy content Toggle raw display
$29$ \( T^{8} \) Copy content Toggle raw display
$31$ \( (T^{2} + 8 T - 29)^{4} \) Copy content Toggle raw display
$37$ \( T^{8} \) Copy content Toggle raw display
$41$ \( T^{8} \) Copy content Toggle raw display
$43$ \( T^{8} \) Copy content Toggle raw display
$47$ \( T^{8} - 202 T^{6} + \cdots + 13845841 \) Copy content Toggle raw display
$53$ \( T^{8} - 298 T^{6} + \cdots + 373301041 \) Copy content Toggle raw display
$59$ \( T^{8} \) Copy content Toggle raw display
$61$ \( (T^{2} + 2 T + 4)^{4} \) Copy content Toggle raw display
$67$ \( T^{8} \) Copy content Toggle raw display
$71$ \( T^{8} \) Copy content Toggle raw display
$73$ \( T^{8} \) Copy content Toggle raw display
$79$ \( (T^{2} - 16 T + 256)^{4} \) Copy content Toggle raw display
$83$ \( (T^{4} + 178 T^{2} + 5041)^{2} \) 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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