Properties

Label 256.8.a.l
Level $256$
Weight $8$
Character orbit 256.a
Self dual yes
Analytic conductor $79.971$
Analytic rank $0$
Dimension $4$
Inner twists $4$

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Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [256,8,Mod(1,256)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(256, base_ring=CyclotomicField(2))
 
chi = DirichletCharacter(H, H._module([0, 0]))
 
N = Newforms(chi, 8, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("256.1");
 
S:= CuspForms(chi, 8);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 256 = 2^{8} \)
Weight: \( k \) \(=\) \( 8 \)
Character orbit: \([\chi]\) \(=\) 256.a (trivial)

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: yes
Analytic conductor: \(79.9705665239\)
Analytic rank: \(0\)
Dimension: \(4\)
Coefficient field: \(\Q(\sqrt{2}, \sqrt{5})\)
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{4} - 6x^{2} + 4 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{7}]\)
Coefficient ring index: \( 2^{10} \)
Twist minimal: no (minimal twist has level 128)
Fricke sign: \(+1\)
Sato-Tate group: $\mathrm{SU}(2)$

$q$-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 \(1,\beta_1,\beta_2,\beta_3\) for the coefficient ring described below. We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q - 3 \beta_1 q^{3} - 17 \beta_{3} q^{5} + 29 \beta_{2} q^{7} - 1827 q^{9} - 1157 \beta_1 q^{11} - 481 \beta_{3} q^{13} + 255 \beta_{2} q^{15} - 8890 q^{17} + 377 \beta_1 q^{19} - 696 \beta_{3} q^{21}+ \cdots + 2113839 \beta_1 q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 4 q - 7308 q^{9} - 35560 q^{17} + 57420 q^{25} + 555360 q^{33} + 491608 q^{41} - 1571804 q^{49} - 180960 q^{57} + 10466560 q^{65} + 15396680 q^{73} + 10202436 q^{81} + 21742344 q^{89} + 24716120 q^{97}+O(q^{100}) \) Copy content Toggle raw display

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

\(\beta_{1}\)\(=\) \( -\nu^{3} + 8\nu \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( 8\nu^{3} - 32\nu \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( 8\nu^{2} - 24 \) Copy content Toggle raw display
\(\nu\)\(=\) \( ( \beta_{2} + 8\beta_1 ) / 32 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( ( \beta_{3} + 24 ) / 8 \) Copy content Toggle raw display
\(\nu^{3}\)\(=\) \( ( \beta_{2} + 4\beta_1 ) / 4 \) Copy content Toggle raw display

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
1.1
2.28825
0.874032
−2.28825
−0.874032
0 −18.9737 0 −304.105 0 656.195 0 −1827.00 0
1.2 0 −18.9737 0 304.105 0 −656.195 0 −1827.00 0
1.3 0 18.9737 0 −304.105 0 −656.195 0 −1827.00 0
1.4 0 18.9737 0 304.105 0 656.195 0 −1827.00 0
\(n\): e.g. 2-40 or 990-1000
Significant digits:
Format:

Atkin-Lehner signs

\( p \) Sign
\(2\) \( +1 \)

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 256.8.a.l 4
4.b odd 2 1 inner 256.8.a.l 4
8.b even 2 1 inner 256.8.a.l 4
8.d odd 2 1 inner 256.8.a.l 4
16.e even 4 2 128.8.b.f 4
16.f odd 4 2 128.8.b.f 4
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
128.8.b.f 4 16.e even 4 2
128.8.b.f 4 16.f odd 4 2
256.8.a.l 4 1.a even 1 1 trivial
256.8.a.l 4 4.b odd 2 1 inner
256.8.a.l 4 8.b even 2 1 inner
256.8.a.l 4 8.d odd 2 1 inner

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{8}^{\mathrm{new}}(\Gamma_0(256))\):

\( T_{3}^{2} - 360 \) Copy content Toggle raw display
\( T_{5}^{2} - 92480 \) Copy content Toggle raw display
\( T_{7}^{2} - 430592 \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{4} \) Copy content Toggle raw display
$3$ \( (T^{2} - 360)^{2} \) Copy content Toggle raw display
$5$ \( (T^{2} - 92480)^{2} \) Copy content Toggle raw display
$7$ \( (T^{2} - 430592)^{2} \) Copy content Toggle raw display
$11$ \( (T^{2} - 53545960)^{2} \) Copy content Toggle raw display
$13$ \( (T^{2} - 74035520)^{2} \) Copy content Toggle raw display
$17$ \( (T + 8890)^{4} \) Copy content Toggle raw display
$19$ \( (T^{2} - 5685160)^{2} \) Copy content Toggle raw display
$23$ \( (T^{2} - 1972924928)^{2} \) Copy content Toggle raw display
$29$ \( (T^{2} - 29056589120)^{2} \) Copy content Toggle raw display
$31$ \( (T^{2} - 11796480000)^{2} \) Copy content Toggle raw display
$37$ \( (T^{2} - 64352243520)^{2} \) Copy content Toggle raw display
$41$ \( (T - 122902)^{4} \) Copy content Toggle raw display
$43$ \( (T^{2} - 755777073960)^{2} \) Copy content Toggle raw display
$47$ \( (T^{2} - 1722011666432)^{2} \) Copy content Toggle raw display
$53$ \( (T^{2} - 1340667049280)^{2} \) Copy content Toggle raw display
$59$ \( (T^{2} - 2341456609960)^{2} \) Copy content Toggle raw display
$61$ \( (T^{2} - 1676019725120)^{2} \) Copy content Toggle raw display
$67$ \( (T^{2} - 638017081000)^{2} \) Copy content Toggle raw display
$71$ \( (T^{2} - 19988394099200)^{2} \) Copy content Toggle raw display
$73$ \( (T - 3849170)^{4} \) Copy content Toggle raw display
$79$ \( (T^{2} - 53777575987200)^{2} \) Copy content Toggle raw display
$83$ \( (T^{2} - 204713140840)^{2} \) Copy content Toggle raw display
$89$ \( (T - 5435586)^{4} \) Copy content Toggle raw display
$97$ \( (T - 6179030)^{4} \) Copy content Toggle raw display
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