Properties

Label 840.2.z.b
Level $840$
Weight $2$
Character orbit 840.z
Analytic conductor $6.707$
Analytic rank $0$
Dimension $4$
Inner twists $2$

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Newspace parameters

Copy content comment:Compute space of new eigenforms
 
Copy content gp:[N,k,chi] = [840,2,Mod(811,840)] mf = mfinit([N,k,chi],0) lf = mfeigenbasis(mf)
 
Copy content sage:from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(840, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([1, 1, 0, 0, 1])) N = Newforms(chi, 2, names="a")
 
Copy content magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code chi := DirichletCharacter("840.811"); S:= CuspForms(chi, 2); N := Newforms(S);
 
Level: \( N \) \(=\) \( 840 = 2^{3} \cdot 3 \cdot 5 \cdot 7 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 840.z (of order \(2\), degree \(1\), minimal)

Newform invariants

Copy content comment:select newform
 
Copy content sage:traces = [4,-4,0,0,4] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(5)] == traces)
 
Copy content gp:f = lf[1] \\ Warning: the index may be different
 
Self dual: no
Analytic conductor: \(6.70743376979\)
Analytic rank: \(0\)
Dimension: \(4\)
Coefficient field: \(\Q(i, \sqrt{6})\)
Copy content comment:defining polynomial
 
Copy content gp:f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{4} + 9 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{7}]\)
Coefficient ring index: \( 2 \)
Twist minimal: yes
Sato-Tate group: $\mathrm{SU}(2)[C_{2}]$

$q$-expansion

Copy content comment:q-expansion
 
Copy content sage:f.q_expansion() # note that sage often uses an isomorphic number field
 
Copy content 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.

\(f(q)\) \(=\) \( q + ( - \beta_1 - 1) q^{2} - \beta_1 q^{3} + 2 \beta_1 q^{4} + q^{5} + (\beta_1 - 1) q^{6} + (\beta_{2} - 1) q^{7} + ( - 2 \beta_1 + 2) q^{8} - q^{9} + ( - \beta_1 - 1) q^{10} + 2 q^{11} + 2 q^{12} + ( - 2 \beta_{3} + 2) q^{13}+ \cdots - 2 q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 4 q - 4 q^{2} + 4 q^{5} - 4 q^{6} - 4 q^{7} + 8 q^{8} - 4 q^{9} - 4 q^{10} + 8 q^{11} + 8 q^{12} + 8 q^{13} + 4 q^{14} - 16 q^{16} + 4 q^{18} - 8 q^{22} - 8 q^{24} + 4 q^{25} - 8 q^{26} - 4 q^{30} + 8 q^{31}+ \cdots - 8 q^{99}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{4} + 9 \) : Copy content Toggle raw display

\(\beta_{1}\)\(=\) \( ( \nu^{2} ) / 3 \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( ( \nu^{3} + 3\nu ) / 3 \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( ( -\nu^{3} + 3\nu ) / 3 \) Copy content Toggle raw display
\(\nu\)\(=\) \( ( \beta_{3} + \beta_{2} ) / 2 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( 3\beta_1 \) Copy content Toggle raw display
\(\nu^{3}\)\(=\) \( ( -3\beta_{3} + 3\beta_{2} ) / 2 \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/840\mathbb{Z}\right)^\times\).

\(n\) \(241\) \(281\) \(337\) \(421\) \(631\)
\(\chi(n)\) \(-1\) \(1\) \(1\) \(-1\) \(-1\)

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.

Copy content comment:embeddings in the coefficient field
 
Copy content gp:mfembed(f)
 
Label   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
811.1
−1.22474 1.22474i
1.22474 + 1.22474i
1.22474 1.22474i
−1.22474 + 1.22474i
−1.00000 1.00000i 1.00000i 2.00000i 1.00000 −1.00000 + 1.00000i −1.00000 2.44949i 2.00000 2.00000i −1.00000 −1.00000 1.00000i
811.2 −1.00000 1.00000i 1.00000i 2.00000i 1.00000 −1.00000 + 1.00000i −1.00000 + 2.44949i 2.00000 2.00000i −1.00000 −1.00000 1.00000i
811.3 −1.00000 + 1.00000i 1.00000i 2.00000i 1.00000 −1.00000 1.00000i −1.00000 2.44949i 2.00000 + 2.00000i −1.00000 −1.00000 + 1.00000i
811.4 −1.00000 + 1.00000i 1.00000i 2.00000i 1.00000 −1.00000 1.00000i −1.00000 + 2.44949i 2.00000 + 2.00000i −1.00000 −1.00000 + 1.00000i
\(n\): e.g. 2-40 or 990-1000
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
56.e even 2 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 840.2.z.b yes 4
4.b odd 2 1 3360.2.z.b 4
7.b odd 2 1 840.2.z.a 4
8.b even 2 1 3360.2.z.a 4
8.d odd 2 1 840.2.z.a 4
28.d even 2 1 3360.2.z.a 4
56.e even 2 1 inner 840.2.z.b yes 4
56.h odd 2 1 3360.2.z.b 4
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
840.2.z.a 4 7.b odd 2 1
840.2.z.a 4 8.d odd 2 1
840.2.z.b yes 4 1.a even 1 1 trivial
840.2.z.b yes 4 56.e even 2 1 inner
3360.2.z.a 4 8.b even 2 1
3360.2.z.a 4 28.d even 2 1
3360.2.z.b 4 4.b odd 2 1
3360.2.z.b 4 56.h odd 2 1

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{2}^{\mathrm{new}}(840, [\chi])\):

\( T_{11} - 2 \) Copy content Toggle raw display
\( T_{13}^{2} - 4T_{13} - 20 \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( (T^{2} + 2 T + 2)^{2} \) Copy content Toggle raw display
$3$ \( (T^{2} + 1)^{2} \) Copy content Toggle raw display
$5$ \( (T - 1)^{4} \) Copy content Toggle raw display
$7$ \( (T^{2} + 2 T + 7)^{2} \) Copy content Toggle raw display
$11$ \( (T - 2)^{4} \) Copy content Toggle raw display
$13$ \( (T^{2} - 4 T - 20)^{2} \) Copy content Toggle raw display
$17$ \( (T^{2} + 24)^{2} \) Copy content Toggle raw display
$19$ \( T^{4} + 56T^{2} + 400 \) Copy content Toggle raw display
$23$ \( (T^{2} + 36)^{2} \) Copy content Toggle raw display
$29$ \( T^{4} + 80T^{2} + 64 \) Copy content Toggle raw display
$31$ \( (T - 2)^{4} \) Copy content Toggle raw display
$37$ \( T^{4} + 200T^{2} + 8464 \) Copy content Toggle raw display
$41$ \( T^{4} + 56T^{2} + 400 \) Copy content Toggle raw display
$43$ \( (T^{2} + 8 T - 8)^{2} \) Copy content Toggle raw display
$47$ \( (T^{2} - 12 T + 12)^{2} \) Copy content Toggle raw display
$53$ \( (T^{2} + 96)^{2} \) Copy content Toggle raw display
$59$ \( T^{4} + 176T^{2} + 1600 \) Copy content Toggle raw display
$61$ \( (T^{2} - 8 T - 8)^{2} \) Copy content Toggle raw display
$67$ \( (T^{2} - 24)^{2} \) Copy content Toggle raw display
$71$ \( T^{4} + 176T^{2} + 1600 \) Copy content Toggle raw display
$73$ \( T^{4} + 80T^{2} + 64 \) Copy content Toggle raw display
$79$ \( (T^{2} + 16)^{2} \) Copy content Toggle raw display
$83$ \( (T^{2} + 16)^{2} \) Copy content Toggle raw display
$89$ \( T^{4} + 120T^{2} + 144 \) Copy content Toggle raw display
$97$ \( T^{4} + 80T^{2} + 64 \) Copy content Toggle raw display
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