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Newspace parameters

Copy content comment:Compute space of new eigenforms
 
Copy content gp:[N,k,chi] = [256,4,Mod(129,256)] 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("256.129"); S:= CuspForms(chi, 4); N := Newforms(S);
 
Copy content sage:from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(256, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 1])) N = Newforms(chi, 4, names="a")
 
Level: \( N \) \(=\) \( 256 = 2^{8} \)
Weight: \( k \) \(=\) \( 4 \)
Character orbit: \([\chi]\) \(=\) 256.b (of order \(2\), degree \(1\), not minimal)

Newform invariants

Copy content comment:select newform
 
Copy content sage:traces = [4,0,0,0,0,0,-16] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(7)] == traces)
 
Copy content gp:f = lf[1] \\ Warning: the index may be different
 
Self dual: no
Analytic conductor: \(15.1044889615\)
Analytic rank: \(0\)
Dimension: \(4\)
Coefficient field: \(\Q(\zeta_{12})\)
Copy content comment:defining polynomial
 
Copy content gp:f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{4} - x^{2} + 1 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{5}]\)
Coefficient ring index: \( 2^{8} \)
Twist minimal: no (minimal twist has level 128)
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.

\(f(q)\) \(=\) \( q + ( - \beta_{2} + \beta_1) q^{3} + (2 \beta_{2} + \beta_1) q^{5} + ( - \beta_{3} - 4) q^{7} + (2 \beta_{3} - 25) q^{9} + ( - \beta_{2} - 23 \beta_1) q^{11} + (6 \beta_{2} - 25 \beta_1) q^{13} + ( - \beta_{3} + 92) q^{15}+ \cdots + ( - 159 \beta_{2} + 479 \beta_1) q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 4 q - 16 q^{7} - 100 q^{9} + 368 q^{15} + 184 q^{17} + 16 q^{23} - 284 q^{25} + 768 q^{31} + 176 q^{33} + 1552 q^{39} + 600 q^{41} + 32 q^{47} - 540 q^{49} + 752 q^{55} + 1328 q^{57} - 1136 q^{63} - 1904 q^{65}+ \cdots + 4408 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring

\(\beta_{1}\)\(=\) \( 2\zeta_{12}^{3} \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( 8\zeta_{12}^{2} - 4 \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( -8\zeta_{12}^{3} + 16\zeta_{12} \) Copy content Toggle raw display
\(\zeta_{12}\)\(=\) \( ( \beta_{3} + 4\beta_1 ) / 16 \) Copy content Toggle raw display
\(\zeta_{12}^{2}\)\(=\) \( ( \beta_{2} + 4 ) / 8 \) Copy content Toggle raw display
\(\zeta_{12}^{3}\)\(=\) \( ( \beta_1 ) / 2 \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/256\mathbb{Z}\right)^\times\).

\(n\) \(5\) \(255\)
\(\chi(n)\) \(-1\) \(1\)

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
129.1
−0.866025 − 0.500000i
0.866025 + 0.500000i
0.866025 − 0.500000i
−0.866025 + 0.500000i
0 − 8.92820i 0 11.8564i 0 9.85641 0 −52.7128 0
129.2 0 − 4.92820i 0 15.8564i 0 −17.8564 0 2.71281 0
129.3 0 4.92820i 0 − 15.8564i 0 −17.8564 0 2.71281 0
129.4 0 8.92820i 0 − 11.8564i 0 9.85641 0 −52.7128 0
\(n\): e.g. 2-40 or 80-90
Significant digits:
Format:

Inner twists

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

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 256.4.b.h 4
4.b odd 2 1 256.4.b.i 4
8.b even 2 1 inner 256.4.b.h 4
8.d odd 2 1 256.4.b.i 4
16.e even 4 1 128.4.a.f yes 2
16.e even 4 1 128.4.a.g yes 2
16.f odd 4 1 128.4.a.e ✓ 2
16.f odd 4 1 128.4.a.h yes 2
48.i odd 4 1 1152.4.a.r 2
48.i odd 4 1 1152.4.a.t 2
48.k even 4 1 1152.4.a.q 2
48.k even 4 1 1152.4.a.s 2
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
128.4.a.e ✓ 2 16.f odd 4 1
128.4.a.f yes 2 16.e even 4 1
128.4.a.g yes 2 16.e even 4 1
128.4.a.h yes 2 16.f odd 4 1
256.4.b.h 4 1.a even 1 1 trivial
256.4.b.h 4 8.b even 2 1 inner
256.4.b.i 4 4.b odd 2 1
256.4.b.i 4 8.d odd 2 1
1152.4.a.q 2 48.k even 4 1
1152.4.a.r 2 48.i odd 4 1
1152.4.a.s 2 48.k even 4 1
1152.4.a.t 2 48.i odd 4 1

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{4}^{\mathrm{new}}(256, [\chi])\):

\( T_{3}^{4} + 104T_{3}^{2} + 1936 \) Copy content Toggle raw display
\( T_{7}^{2} + 8T_{7} - 176 \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{4} \) Copy content Toggle raw display
$3$ \( T^{4} + 104T^{2} + 1936 \) Copy content Toggle raw display
$5$ \( T^{4} + 392 T^{2} + 35344 \) Copy content Toggle raw display
$7$ \( (T^{2} + 8 T - 176)^{2} \) Copy content Toggle raw display
$11$ \( T^{4} + 4328 T^{2} + 4276624 \) Copy content Toggle raw display
$13$ \( T^{4} + 8456 T^{2} + 595984 \) Copy content Toggle raw display
$17$ \( (T^{2} - 92 T - 4796)^{2} \) Copy content Toggle raw display
$19$ \( T^{4} + 4712 T^{2} + 5513104 \) Copy content Toggle raw display
$23$ \( (T^{2} - 8 T - 15536)^{2} \) Copy content Toggle raw display
$29$ \( T^{4} + 13128 T^{2} + 9217296 \) Copy content Toggle raw display
$31$ \( (T^{2} - 384 T + 24576)^{2} \) Copy content Toggle raw display
$37$ \( T^{4} + 33608 T^{2} + 4048144 \) Copy content Toggle raw display
$41$ \( (T^{2} - 300 T + 19428)^{2} \) Copy content Toggle raw display
$43$ \( T^{4} + 47400 T^{2} + 453690000 \) Copy content Toggle raw display
$47$ \( (T^{2} - 16 T - 92864)^{2} \) Copy content Toggle raw display
$53$ \( T^{4} + 18888 T^{2} + 87834384 \) Copy content Toggle raw display
$59$ \( T^{4} + \cdots + 2643193744 \) Copy content Toggle raw display
$61$ \( T^{4} + \cdots + 45746365456 \) Copy content Toggle raw display
$67$ \( T^{4} + \cdots + 104507372176 \) Copy content Toggle raw display
$71$ \( (T^{2} - 408 T - 43056)^{2} \) Copy content Toggle raw display
$73$ \( (T^{2} + 412 T - 87356)^{2} \) Copy content Toggle raw display
$79$ \( (T^{2} - 400 T - 22208)^{2} \) Copy content Toggle raw display
$83$ \( T^{4} + \cdots + 46899966096 \) Copy content Toggle raw display
$89$ \( (T^{2} + 572 T - 564092)^{2} \) Copy content Toggle raw display
$97$ \( (T^{2} - 2204 T + 808132)^{2} \) Copy content Toggle raw display
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