Properties

Label 640.2.d.a
Level $640$
Weight $2$
Character orbit 640.d
Analytic conductor $5.110$
Analytic rank $0$
Dimension $4$
CM no
Inner twists $4$

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Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [640,2,Mod(321,640)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(640, base_ring=CyclotomicField(2))
 
chi = DirichletCharacter(H, H._module([0, 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("640.321");
 
S:= CuspForms(chi, 2);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 640 = 2^{7} \cdot 5 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 640.d (of order \(2\), degree \(1\), 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: \(5.11042572936\)
Analytic rank: \(0\)
Dimension: \(4\)
Coefficient field: \(\Q(i, \sqrt{10})\)
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{4} + 25 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{5}]\)
Coefficient ring index: \( 2 \)
Twist minimal: yes
Sato-Tate group: $\mathrm{SU}(2)[C_{2}]$

$q$-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.

\(f(q)\) \(=\) \( q - \beta_{2} q^{3} + \beta_1 q^{5} + \beta_{3} q^{7} - 7 q^{9}+O(q^{10}) \) Copy content Toggle raw display \( q - \beta_{2} q^{3} + \beta_1 q^{5} + \beta_{3} q^{7} - 7 q^{9} - 6 \beta_1 q^{13} + \beta_{3} q^{15} - 2 q^{17} - 2 \beta_{2} q^{19} - 10 \beta_1 q^{21} + \beta_{3} q^{23} - q^{25} + 4 \beta_{2} q^{27} + 4 \beta_1 q^{29} - 2 \beta_{3} q^{31} + \beta_{2} q^{35} + 2 \beta_1 q^{37} - 6 \beta_{3} q^{39} - \beta_{2} q^{43} - 7 \beta_1 q^{45} + 3 \beta_{3} q^{47} + 3 q^{49} + 2 \beta_{2} q^{51} + 6 \beta_1 q^{53} - 20 q^{57} - 2 \beta_{2} q^{59} - 2 \beta_1 q^{61} - 7 \beta_{3} q^{63} + 6 q^{65} + 3 \beta_{2} q^{67} - 10 \beta_1 q^{69} + 2 \beta_{3} q^{71} - 14 q^{73} + \beta_{2} q^{75} + 4 \beta_{3} q^{79} + 19 q^{81} + \beta_{2} q^{83} - 2 \beta_1 q^{85} + 4 \beta_{3} q^{87} + 10 q^{89} - 6 \beta_{2} q^{91} + 20 \beta_1 q^{93} + 2 \beta_{3} q^{95} + 2 q^{97}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 4 q - 28 q^{9}+O(q^{10}) \) Copy content Toggle raw display \( 4 q - 28 q^{9} - 8 q^{17} - 4 q^{25} + 12 q^{49} - 80 q^{57} + 24 q^{65} - 56 q^{73} + 76 q^{81} + 40 q^{89} + 8 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{4} + 25 \) : Copy content Toggle raw display

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

comment: embeddings in the coefficient field
 
gp: mfembed(f)
 
Label   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
321.1
−1.58114 + 1.58114i
1.58114 + 1.58114i
1.58114 1.58114i
−1.58114 1.58114i
0 3.16228i 0 1.00000i 0 −3.16228 0 −7.00000 0
321.2 0 3.16228i 0 1.00000i 0 3.16228 0 −7.00000 0
321.3 0 3.16228i 0 1.00000i 0 3.16228 0 −7.00000 0
321.4 0 3.16228i 0 1.00000i 0 −3.16228 0 −7.00000 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 640.2.d.a 4
3.b odd 2 1 5760.2.k.t 4
4.b odd 2 1 inner 640.2.d.a 4
5.b even 2 1 3200.2.d.j 4
5.c odd 4 1 3200.2.f.p 4
5.c odd 4 1 3200.2.f.q 4
8.b even 2 1 inner 640.2.d.a 4
8.d odd 2 1 inner 640.2.d.a 4
12.b even 2 1 5760.2.k.t 4
16.e even 4 1 1280.2.a.h 2
16.e even 4 1 1280.2.a.l 2
16.f odd 4 1 1280.2.a.h 2
16.f odd 4 1 1280.2.a.l 2
20.d odd 2 1 3200.2.d.j 4
20.e even 4 1 3200.2.f.p 4
20.e even 4 1 3200.2.f.q 4
24.f even 2 1 5760.2.k.t 4
24.h odd 2 1 5760.2.k.t 4
40.e odd 2 1 3200.2.d.j 4
40.f even 2 1 3200.2.d.j 4
40.i odd 4 1 3200.2.f.p 4
40.i odd 4 1 3200.2.f.q 4
40.k even 4 1 3200.2.f.p 4
40.k even 4 1 3200.2.f.q 4
80.k odd 4 1 6400.2.a.bz 2
80.k odd 4 1 6400.2.a.ca 2
80.q even 4 1 6400.2.a.bz 2
80.q even 4 1 6400.2.a.ca 2
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
640.2.d.a 4 1.a even 1 1 trivial
640.2.d.a 4 4.b odd 2 1 inner
640.2.d.a 4 8.b even 2 1 inner
640.2.d.a 4 8.d odd 2 1 inner
1280.2.a.h 2 16.e even 4 1
1280.2.a.h 2 16.f odd 4 1
1280.2.a.l 2 16.e even 4 1
1280.2.a.l 2 16.f odd 4 1
3200.2.d.j 4 5.b even 2 1
3200.2.d.j 4 20.d odd 2 1
3200.2.d.j 4 40.e odd 2 1
3200.2.d.j 4 40.f even 2 1
3200.2.f.p 4 5.c odd 4 1
3200.2.f.p 4 20.e even 4 1
3200.2.f.p 4 40.i odd 4 1
3200.2.f.p 4 40.k even 4 1
3200.2.f.q 4 5.c odd 4 1
3200.2.f.q 4 20.e even 4 1
3200.2.f.q 4 40.i odd 4 1
3200.2.f.q 4 40.k even 4 1
5760.2.k.t 4 3.b odd 2 1
5760.2.k.t 4 12.b even 2 1
5760.2.k.t 4 24.f even 2 1
5760.2.k.t 4 24.h odd 2 1
6400.2.a.bz 2 80.k odd 4 1
6400.2.a.bz 2 80.q even 4 1
6400.2.a.ca 2 80.k odd 4 1
6400.2.a.ca 2 80.q even 4 1

Hecke kernels

This newform subspace can be constructed as the intersection of the kernels of the following linear operators acting on \(S_{2}^{\mathrm{new}}(640, [\chi])\):

\( T_{3}^{2} + 10 \) Copy content Toggle raw display
\( T_{7}^{2} - 10 \) Copy content Toggle raw display
\( T_{11} \) Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{4} \) Copy content Toggle raw display
$3$ \( (T^{2} + 10)^{2} \) Copy content Toggle raw display
$5$ \( (T^{2} + 1)^{2} \) Copy content Toggle raw display
$7$ \( (T^{2} - 10)^{2} \) Copy content Toggle raw display
$11$ \( T^{4} \) Copy content Toggle raw display
$13$ \( (T^{2} + 36)^{2} \) Copy content Toggle raw display
$17$ \( (T + 2)^{4} \) Copy content Toggle raw display
$19$ \( (T^{2} + 40)^{2} \) Copy content Toggle raw display
$23$ \( (T^{2} - 10)^{2} \) Copy content Toggle raw display
$29$ \( (T^{2} + 16)^{2} \) Copy content Toggle raw display
$31$ \( (T^{2} - 40)^{2} \) Copy content Toggle raw display
$37$ \( (T^{2} + 4)^{2} \) Copy content Toggle raw display
$41$ \( T^{4} \) Copy content Toggle raw display
$43$ \( (T^{2} + 10)^{2} \) Copy content Toggle raw display
$47$ \( (T^{2} - 90)^{2} \) Copy content Toggle raw display
$53$ \( (T^{2} + 36)^{2} \) Copy content Toggle raw display
$59$ \( (T^{2} + 40)^{2} \) Copy content Toggle raw display
$61$ \( (T^{2} + 4)^{2} \) Copy content Toggle raw display
$67$ \( (T^{2} + 90)^{2} \) Copy content Toggle raw display
$71$ \( (T^{2} - 40)^{2} \) Copy content Toggle raw display
$73$ \( (T + 14)^{4} \) Copy content Toggle raw display
$79$ \( (T^{2} - 160)^{2} \) Copy content Toggle raw display
$83$ \( (T^{2} + 10)^{2} \) Copy content Toggle raw display
$89$ \( (T - 10)^{4} \) Copy content Toggle raw display
$97$ \( (T - 2)^{4} \) Copy content Toggle raw display
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