Properties

Label 855.2.n.c
Level $855$
Weight $2$
Character orbit 855.n
Analytic conductor $6.827$
Analytic rank $0$
Dimension $8$
Inner twists $4$

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Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [855,2,Mod(647,855)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(855, base_ring=CyclotomicField(4))
 
chi = DirichletCharacter(H, H._module([2, 1, 0]))
 
N = Newforms(chi, 2, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("855.647");
 
S:= CuspForms(chi, 2);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 855 = 3^{2} \cdot 5 \cdot 19 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 855.n (of order \(4\), 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 \(\Q(i)\)
Coefficient field: \(\Q(\zeta_{24})\)
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{8} - x^{4} + 1 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{7}]\)
Coefficient ring index: \( 1 \)
Twist minimal: yes
Sato-Tate group: $\mathrm{SU}(2)[C_{4}]$

$q$-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 primitive root of unity \(\zeta_{24}\). We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + ( - 2 \zeta_{24}^{5} + 2 \zeta_{24}) q^{2} - 2 \zeta_{24}^{6} q^{4} + (2 \zeta_{24}^{7} + \cdots - 2 \zeta_{24}^{3}) q^{5} + (2 \zeta_{24}^{6} - \zeta_{24}^{4} + \cdots + 2) q^{7} + (4 \zeta_{24}^{4} + 2 \zeta_{24}^{2} - 4) q^{10} + \cdots + ( - 6 \zeta_{24}^{5} + \cdots - 6 \zeta_{24}) q^{98} +O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 8 q + 12 q^{7} - 16 q^{10} - 8 q^{13} + 32 q^{16} + 24 q^{22} - 16 q^{25} + 24 q^{28} - 32 q^{31} - 4 q^{43} + 16 q^{52} - 48 q^{55} - 16 q^{58} + 8 q^{61} + 48 q^{67} - 24 q^{70} - 52 q^{73} - 16 q^{76}+ \cdots + 24 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Character values

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

\(n\) \(172\) \(191\) \(496\)
\(\chi(n)\) \(\zeta_{24}^{6}\) \(-1\) \(1\)

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
647.1
0.258819 + 0.965926i
−0.965926 0.258819i
0.965926 + 0.258819i
−0.258819 0.965926i
0.258819 0.965926i
−0.965926 + 0.258819i
0.965926 0.258819i
−0.258819 + 0.965926i
−1.41421 + 1.41421i 0 2.00000i 0.448288 + 2.19067i 0 2.36603 + 2.36603i 0 0 −3.73205 2.46410i
647.2 −1.41421 + 1.41421i 0 2.00000i 1.67303 1.48356i 0 0.633975 + 0.633975i 0 0 −0.267949 + 4.46410i
647.3 1.41421 1.41421i 0 2.00000i −1.67303 + 1.48356i 0 0.633975 + 0.633975i 0 0 −0.267949 + 4.46410i
647.4 1.41421 1.41421i 0 2.00000i −0.448288 2.19067i 0 2.36603 + 2.36603i 0 0 −3.73205 2.46410i
818.1 −1.41421 1.41421i 0 2.00000i 0.448288 2.19067i 0 2.36603 2.36603i 0 0 −3.73205 + 2.46410i
818.2 −1.41421 1.41421i 0 2.00000i 1.67303 + 1.48356i 0 0.633975 0.633975i 0 0 −0.267949 4.46410i
818.3 1.41421 + 1.41421i 0 2.00000i −1.67303 1.48356i 0 0.633975 0.633975i 0 0 −0.267949 4.46410i
818.4 1.41421 + 1.41421i 0 2.00000i −0.448288 + 2.19067i 0 2.36603 2.36603i 0 0 −3.73205 + 2.46410i
\(n\): e.g. 2-40 or 990-1000
Embeddings: e.g. 1-3 or 647.4
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
3.b odd 2 1 inner
5.c odd 4 1 inner
15.e even 4 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 855.2.n.c 8
3.b odd 2 1 inner 855.2.n.c 8
5.c odd 4 1 inner 855.2.n.c 8
15.e even 4 1 inner 855.2.n.c 8
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
855.2.n.c 8 1.a even 1 1 trivial
855.2.n.c 8 3.b odd 2 1 inner
855.2.n.c 8 5.c odd 4 1 inner
855.2.n.c 8 15.e even 4 1 inner

Hecke kernels

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

\( T_{2}^{4} + 16 \) Copy content Toggle raw display
\( T_{7}^{4} - 6T_{7}^{3} + 18T_{7}^{2} - 18T_{7} + 9 \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( (T^{4} + 16)^{2} \) Copy content Toggle raw display
$3$ \( T^{8} \) Copy content Toggle raw display
$5$ \( T^{8} + 8 T^{6} + \cdots + 625 \) Copy content Toggle raw display
$7$ \( (T^{4} - 6 T^{3} + 18 T^{2} + \cdots + 9)^{2} \) Copy content Toggle raw display
$11$ \( (T^{4} + 36 T^{2} + 81)^{2} \) Copy content Toggle raw display
$13$ \( (T^{4} + 4 T^{3} + 8 T^{2} + \cdots + 16)^{2} \) Copy content Toggle raw display
$17$ \( T^{8} + 1746T^{4} + 81 \) Copy content Toggle raw display
$19$ \( (T^{2} + 1)^{4} \) Copy content Toggle raw display
$23$ \( (T^{4} + 144)^{2} \) Copy content Toggle raw display
$29$ \( (T^{4} - 112 T^{2} + 2704)^{2} \) Copy content Toggle raw display
$31$ \( (T^{2} + 8 T + 4)^{4} \) Copy content Toggle raw display
$37$ \( (T^{4} + 576)^{2} \) Copy content Toggle raw display
$41$ \( (T^{2} + 8)^{4} \) Copy content Toggle raw display
$43$ \( (T^{4} + 2 T^{3} + \cdots + 169)^{2} \) Copy content Toggle raw display
$47$ \( T^{8} + 194T^{4} + 1 \) Copy content Toggle raw display
$53$ \( (T^{4} + 1296)^{2} \) Copy content Toggle raw display
$59$ \( (T^{4} - 192 T^{2} + 2304)^{2} \) Copy content Toggle raw display
$61$ \( (T^{2} - 2 T - 191)^{4} \) Copy content Toggle raw display
$67$ \( (T^{4} - 24 T^{3} + \cdots + 2304)^{2} \) Copy content Toggle raw display
$71$ \( (T^{4} + 112 T^{2} + 64)^{2} \) Copy content Toggle raw display
$73$ \( (T^{4} + 26 T^{3} + \cdots + 5041)^{2} \) Copy content Toggle raw display
$79$ \( (T^{4} + 224 T^{2} + 7744)^{2} \) Copy content Toggle raw display
$83$ \( T^{8} + 49664 T^{4} + 65536 \) Copy content Toggle raw display
$89$ \( (T^{4} - 112 T^{2} + 2704)^{2} \) Copy content Toggle raw display
$97$ \( (T^{4} - 12 T^{3} + \cdots + 17424)^{2} \) Copy content Toggle raw display
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