Properties

Label 640.4.d.f
Level $640$
Weight $4$
Character orbit 640.d
Analytic conductor $37.761$
Analytic rank $0$
Dimension $4$
Inner twists $4$

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Newspace parameters

Copy content comment:Compute space of new eigenforms
 
Copy content gp:[N,k,chi] = [640,4,Mod(321,640)] mf = mfinit([N,k,chi],0) lf = mfeigenbasis(mf)
 
Copy content magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code chi := DirichletCharacter("640.321"); S:= CuspForms(chi, 4); N := Newforms(S);
 
Copy content sage:from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(640, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 1, 0])) N = Newforms(chi, 4, names="a")
 
Level: \( N \) \(=\) \( 640 = 2^{7} \cdot 5 \)
Weight: \( k \) \(=\) \( 4 \)
Character orbit: \([\chi]\) \(=\) 640.d (of order \(2\), degree \(1\), minimal)

Newform invariants

Copy content comment:select newform
 
Copy content sage:traces = [4,0,0,0,0,0,0,0,100,0,0,0,0,0,0,0,168] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(17)] == traces)
 
Copy content gp:f = lf[1] \\ Warning: the index may be different
 
Self dual: no
Analytic conductor: \(37.7612224037\)
Analytic rank: \(0\)
Dimension: \(4\)
Coefficient field: \(\Q(\zeta_{8})\)
Copy content comment:defining polynomial
 
Copy content gp:f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{4} + 1 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{5}]\)
Coefficient ring index: \( 2\cdot 5^{2} \)
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.

\(f(q)\) \(=\) \( q + \beta_{2} q^{3} - \beta_1 q^{5} + 3 \beta_{3} q^{7} + 25 q^{9} + 22 \beta_{2} q^{11} - 6 \beta_1 q^{13} + \beta_{3} q^{15} + 42 q^{17} - 24 \beta_{2} q^{19} + 6 \beta_1 q^{21} + 3 \beta_{3} q^{23}+ \cdots + 550 \beta_{2} q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 4 q + 100 q^{9} + 168 q^{17} - 100 q^{25} - 176 q^{33} - 1344 q^{41} + 428 q^{49} + 192 q^{57} - 600 q^{65} + 2296 q^{73} + 2284 q^{81} + 552 q^{89} - 1000 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring

\(\beta_{1}\)\(=\) \( 5\zeta_{8}^{2} \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( \zeta_{8}^{3} + \zeta_{8} \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( -5\zeta_{8}^{3} + 5\zeta_{8} \) Copy content Toggle raw display
\(\zeta_{8}\)\(=\) \( ( \beta_{3} + 5\beta_{2} ) / 10 \) Copy content Toggle raw display
\(\zeta_{8}^{2}\)\(=\) \( ( \beta_1 ) / 5 \) Copy content Toggle raw display
\(\zeta_{8}^{3}\)\(=\) \( ( -\beta_{3} + 5\beta_{2} ) / 10 \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/640\mathbb{Z}\right)^\times\).

\(n\) \(257\) \(261\) \(511\)
\(\chi(n)\) \(1\) \(-1\) \(1\)

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.

Copy content comment:embeddings in the coefficient field
 
Copy content gp:mfembed(f)
 
Label   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
321.1
−0.707107 0.707107i
0.707107 0.707107i
0.707107 + 0.707107i
−0.707107 + 0.707107i
0 1.41421i 0 5.00000i 0 −21.2132 0 25.0000 0
321.2 0 1.41421i 0 5.00000i 0 21.2132 0 25.0000 0
321.3 0 1.41421i 0 5.00000i 0 21.2132 0 25.0000 0
321.4 0 1.41421i 0 5.00000i 0 −21.2132 0 25.0000 0
\(n\): e.g. 2-40 or 990-1000
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
4.b odd 2 1 inner
8.b even 2 1 inner
8.d odd 2 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 640.4.d.f 4
4.b odd 2 1 inner 640.4.d.f 4
8.b even 2 1 inner 640.4.d.f 4
8.d odd 2 1 inner 640.4.d.f 4
16.e even 4 1 1280.4.a.c 2
16.e even 4 1 1280.4.a.i 2
16.f odd 4 1 1280.4.a.c 2
16.f odd 4 1 1280.4.a.i 2
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
640.4.d.f 4 1.a even 1 1 trivial
640.4.d.f 4 4.b odd 2 1 inner
640.4.d.f 4 8.b even 2 1 inner
640.4.d.f 4 8.d odd 2 1 inner
1280.4.a.c 2 16.e even 4 1
1280.4.a.c 2 16.f odd 4 1
1280.4.a.i 2 16.e even 4 1
1280.4.a.i 2 16.f odd 4 1

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{4}^{\mathrm{new}}(640, [\chi])\):

\( T_{3}^{2} + 2 \) Copy content Toggle raw display
\( T_{7}^{2} - 450 \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{4} \) Copy content Toggle raw display
$3$ \( (T^{2} + 2)^{2} \) Copy content Toggle raw display
$5$ \( (T^{2} + 25)^{2} \) Copy content Toggle raw display
$7$ \( (T^{2} - 450)^{2} \) Copy content Toggle raw display
$11$ \( (T^{2} + 968)^{2} \) Copy content Toggle raw display
$13$ \( (T^{2} + 900)^{2} \) Copy content Toggle raw display
$17$ \( (T - 42)^{4} \) Copy content Toggle raw display
$19$ \( (T^{2} + 1152)^{2} \) Copy content Toggle raw display
$23$ \( (T^{2} - 450)^{2} \) Copy content Toggle raw display
$29$ \( T^{4} \) Copy content Toggle raw display
$31$ \( (T^{2} - 1800)^{2} \) Copy content Toggle raw display
$37$ \( (T^{2} + 900)^{2} \) Copy content Toggle raw display
$41$ \( (T + 336)^{4} \) Copy content Toggle raw display
$43$ \( (T^{2} + 27378)^{2} \) Copy content Toggle raw display
$47$ \( (T^{2} - 238050)^{2} \) Copy content Toggle raw display
$53$ \( (T^{2} + 476100)^{2} \) Copy content Toggle raw display
$59$ \( (T^{2} + 320000)^{2} \) Copy content Toggle raw display
$61$ \( (T^{2} + 476100)^{2} \) Copy content Toggle raw display
$67$ \( (T^{2} + 15138)^{2} \) Copy content Toggle raw display
$71$ \( (T^{2} - 952200)^{2} \) Copy content Toggle raw display
$73$ \( (T - 574)^{4} \) Copy content Toggle raw display
$79$ \( (T^{2} - 1036800)^{2} \) Copy content Toggle raw display
$83$ \( (T^{2} + 305762)^{2} \) Copy content Toggle raw display
$89$ \( (T - 138)^{4} \) Copy content Toggle raw display
$97$ \( (T + 250)^{4} \) Copy content Toggle raw display
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