Properties

Label 420.2.f.a
Level $420$
Weight $2$
Character orbit 420.f
Analytic conductor $3.354$
Analytic rank $0$
Dimension $8$
CM discriminant -35
Inner twists $8$

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Show commands: Magma / PariGP / SageMath

Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [420,2,Mod(209,420)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(420, base_ring=CyclotomicField(2))
 
chi = DirichletCharacter(H, H._module([0, 1, 1, 1]))
 
N = Newforms(chi, 2, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("420.209");
 
S:= CuspForms(chi, 2);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 420 = 2^{2} \cdot 3 \cdot 5 \cdot 7 \)
Weight: \( k \) \(=\) \( 2 \)
Character orbit: \([\chi]\) \(=\) 420.f (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: \(3.35371688489\)
Analytic rank: \(0\)
Dimension: \(8\)
Coefficient field: 8.0.31116960000.2
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{8} + x^{6} - 8x^{4} + 9x^{2} + 81 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{5}]\)
Coefficient ring index: \( 2^{2}\cdot 3^{2} \)
Twist minimal: yes
Sato-Tate group: $\mathrm{U}(1)[D_{2}]$

$q$-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 \(1,\beta_1,\ldots,\beta_{7}\) for the coefficient ring described below. We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + \beta_1 q^{3} + \beta_{4} q^{5} + ( - \beta_{6} - \beta_1) q^{7} + \beta_{2} q^{9}+O(q^{10}) \) Copy content Toggle raw display \( q + \beta_1 q^{3} + \beta_{4} q^{5} + ( - \beta_{6} - \beta_1) q^{7} + \beta_{2} q^{9} + \beta_{5} q^{11} + ( - \beta_{7} - \beta_{6} + \cdots + 2 \beta_1) q^{13}+ \cdots + ( - 3 \beta_{5} - \beta_{2} + 3) q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 8 q - 2 q^{9}+O(q^{10}) \) Copy content Toggle raw display \( 8 q - 2 q^{9} + 10 q^{15} - 14 q^{21} - 40 q^{25} + 38 q^{39} + 56 q^{49} - 58 q^{51} + 4 q^{79} + 34 q^{81} - 20 q^{85} + 28 q^{91} + 26 q^{99}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{8} + x^{6} - 8x^{4} + 9x^{2} + 81 \) : Copy content Toggle raw display

\(\beta_{1}\)\(=\) \( \nu \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( \nu^{2} \) Copy content Toggle raw display
\(\beta_{3}\)\(=\) \( ( \nu^{6} + 4\nu^{4} - 8\nu^{2} - 3 ) / 12 \) Copy content Toggle raw display
\(\beta_{4}\)\(=\) \( ( -\nu^{7} + 8\nu^{5} + 44\nu^{3} - 81\nu ) / 108 \) Copy content Toggle raw display
\(\beta_{5}\)\(=\) \( ( -\nu^{6} + 2\nu^{4} + 2\nu^{2} - 21 ) / 6 \) Copy content Toggle raw display
\(\beta_{6}\)\(=\) \( ( \nu^{7} - 8\nu^{5} + 10\nu^{3} + 27\nu ) / 54 \) Copy content Toggle raw display
\(\beta_{7}\)\(=\) \( ( 13\nu^{7} + 4\nu^{5} - 32\nu^{3} + 189\nu ) / 108 \) Copy content Toggle raw display
\(\nu\)\(=\) \( \beta_1 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( \beta_{2} \) Copy content Toggle raw display
\(\nu^{3}\)\(=\) \( \beta_{6} + 2\beta_{4} + \beta_1 \) Copy content Toggle raw display
\(\nu^{4}\)\(=\) \( \beta_{5} + 2\beta_{3} + \beta_{2} + 4 \) Copy content Toggle raw display
\(\nu^{5}\)\(=\) \( \beta_{7} - 5\beta_{6} + 3\beta_{4} + 3\beta_1 \) Copy content Toggle raw display
\(\nu^{6}\)\(=\) \( -4\beta_{5} + 4\beta_{3} + 4\beta_{2} - 13 \) Copy content Toggle raw display
\(\nu^{7}\)\(=\) \( 8\beta_{7} + 4\beta_{6} + 4\beta_{4} - 13\beta_1 \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/420\mathbb{Z}\right)^\times\).

\(n\) \(211\) \(241\) \(281\) \(337\)
\(\chi(n)\) \(1\) \(-1\) \(-1\) \(-1\)

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.

comment: embeddings in the coefficient field
 
gp: mfembed(f)
 
Label   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
209.1
−1.62968 0.586627i
−1.62968 + 0.586627i
−0.306808 1.70466i
−0.306808 + 1.70466i
0.306808 1.70466i
0.306808 + 1.70466i
1.62968 0.586627i
1.62968 + 0.586627i
0 −1.62968 0.586627i 0 2.23607i 0 2.64575 0 2.31174 + 1.91203i 0
209.2 0 −1.62968 + 0.586627i 0 2.23607i 0 2.64575 0 2.31174 1.91203i 0
209.3 0 −0.306808 1.70466i 0 2.23607i 0 −2.64575 0 −2.81174 + 1.04601i 0
209.4 0 −0.306808 + 1.70466i 0 2.23607i 0 −2.64575 0 −2.81174 1.04601i 0
209.5 0 0.306808 1.70466i 0 2.23607i 0 2.64575 0 −2.81174 1.04601i 0
209.6 0 0.306808 + 1.70466i 0 2.23607i 0 2.64575 0 −2.81174 + 1.04601i 0
209.7 0 1.62968 0.586627i 0 2.23607i 0 −2.64575 0 2.31174 1.91203i 0
209.8 0 1.62968 + 0.586627i 0 2.23607i 0 −2.64575 0 2.31174 + 1.91203i 0
\(n\): e.g. 2-40 or 990-1000
Embeddings: e.g. 1-3 or 209.8
Significant digits:
Format:

Inner twists

Char Parity Ord Mult Type
1.a even 1 1 trivial
35.c odd 2 1 CM by \(\Q(\sqrt{-35}) \)
3.b odd 2 1 inner
5.b even 2 1 inner
7.b odd 2 1 inner
15.d odd 2 1 inner
21.c even 2 1 inner
105.g even 2 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 420.2.f.a 8
3.b odd 2 1 inner 420.2.f.a 8
4.b odd 2 1 1680.2.k.d 8
5.b even 2 1 inner 420.2.f.a 8
5.c odd 4 2 2100.2.d.j 8
7.b odd 2 1 inner 420.2.f.a 8
12.b even 2 1 1680.2.k.d 8
15.d odd 2 1 inner 420.2.f.a 8
15.e even 4 2 2100.2.d.j 8
20.d odd 2 1 1680.2.k.d 8
21.c even 2 1 inner 420.2.f.a 8
28.d even 2 1 1680.2.k.d 8
35.c odd 2 1 CM 420.2.f.a 8
35.f even 4 2 2100.2.d.j 8
60.h even 2 1 1680.2.k.d 8
84.h odd 2 1 1680.2.k.d 8
105.g even 2 1 inner 420.2.f.a 8
105.k odd 4 2 2100.2.d.j 8
140.c even 2 1 1680.2.k.d 8
420.o odd 2 1 1680.2.k.d 8
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
420.2.f.a 8 1.a even 1 1 trivial
420.2.f.a 8 3.b odd 2 1 inner
420.2.f.a 8 5.b even 2 1 inner
420.2.f.a 8 7.b odd 2 1 inner
420.2.f.a 8 15.d odd 2 1 inner
420.2.f.a 8 21.c even 2 1 inner
420.2.f.a 8 35.c odd 2 1 CM
420.2.f.a 8 105.g even 2 1 inner
1680.2.k.d 8 4.b odd 2 1
1680.2.k.d 8 12.b even 2 1
1680.2.k.d 8 20.d odd 2 1
1680.2.k.d 8 28.d even 2 1
1680.2.k.d 8 60.h even 2 1
1680.2.k.d 8 84.h odd 2 1
1680.2.k.d 8 140.c even 2 1
1680.2.k.d 8 420.o odd 2 1
2100.2.d.j 8 5.c odd 4 2
2100.2.d.j 8 15.e even 4 2
2100.2.d.j 8 35.f even 4 2
2100.2.d.j 8 105.k odd 4 2

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{11}^{4} + 31T_{11}^{2} + 4 \) acting on \(S_{2}^{\mathrm{new}}(420, [\chi])\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{8} \) Copy content Toggle raw display
$3$ \( T^{8} + T^{6} + \cdots + 81 \) Copy content Toggle raw display
$5$ \( (T^{2} + 5)^{4} \) Copy content Toggle raw display
$7$ \( (T^{2} - 7)^{4} \) Copy content Toggle raw display
$11$ \( (T^{4} + 31 T^{2} + 4)^{2} \) Copy content Toggle raw display
$13$ \( (T^{4} - 71 T^{2} + 1024)^{2} \) Copy content Toggle raw display
$17$ \( (T^{4} + 97 T^{2} + 2116)^{2} \) Copy content Toggle raw display
$19$ \( T^{8} \) Copy content Toggle raw display
$23$ \( T^{8} \) Copy content Toggle raw display
$29$ \( (T^{4} + 139 T^{2} + 2704)^{2} \) Copy content Toggle raw display
$31$ \( T^{8} \) Copy content Toggle raw display
$37$ \( T^{8} \) Copy content Toggle raw display
$41$ \( T^{8} \) Copy content Toggle raw display
$43$ \( T^{8} \) Copy content Toggle raw display
$47$ \( (T^{4} + 157 T^{2} + 256)^{2} \) Copy content Toggle raw display
$53$ \( T^{8} \) Copy content Toggle raw display
$59$ \( T^{8} \) Copy content Toggle raw display
$61$ \( T^{8} \) Copy content Toggle raw display
$67$ \( T^{8} \) Copy content Toggle raw display
$71$ \( (T^{2} + 140)^{4} \) Copy content Toggle raw display
$73$ \( (T^{2} - 112)^{4} \) Copy content Toggle raw display
$79$ \( (T^{2} - T - 236)^{4} \) Copy content Toggle raw display
$83$ \( (T^{2} + 80)^{4} \) Copy content Toggle raw display
$89$ \( T^{8} \) Copy content Toggle raw display
$97$ \( (T^{4} - 239 T^{2} + 2704)^{2} \) Copy content Toggle raw display
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