Properties

Label 81.4.c.b
Level $81$
Weight $4$
Character orbit 81.c
Analytic conductor $4.779$
Analytic rank $0$
Dimension $2$
CM discriminant -3
Inner twists $4$

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Show commands: Magma / PariGP / SageMath

Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [81,4,Mod(28,81)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(81, base_ring=CyclotomicField(6))
 
chi = DirichletCharacter(H, H._module([2]))
 
N = Newforms(chi, 4, names="a")
 
//Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
 
chi := DirichletCharacter("81.28");
 
S:= CuspForms(chi, 4);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 81 = 3^{4} \)
Weight: \( k \) \(=\) \( 4 \)
Character orbit: \([\chi]\) \(=\) 81.c (of order \(3\), degree \(2\), not 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: \(4.77915471046\)
Analytic rank: \(0\)
Dimension: \(2\)
Coefficient field: \(\Q(\sqrt{-3}) \)
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{2} - x + 1 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{25}]\)
Coefficient ring index: \( 1 \)
Twist minimal: no (minimal twist has level 9)
Sato-Tate group: $\mathrm{U}(1)[D_{3}]$

$q$-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 primitive root of unity \(\zeta_{6}\). We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + 8 \zeta_{6} q^{4} + (20 \zeta_{6} - 20) q^{7}+O(q^{10}) \) Copy content Toggle raw display \( q + 8 \zeta_{6} q^{4} + (20 \zeta_{6} - 20) q^{7} + 70 \zeta_{6} q^{13} + (64 \zeta_{6} - 64) q^{16} + 56 q^{19} + ( - 125 \zeta_{6} + 125) q^{25} - 160 q^{28} - 308 \zeta_{6} q^{31} + 110 q^{37} + ( - 520 \zeta_{6} + 520) q^{43} - 57 \zeta_{6} q^{49} + (560 \zeta_{6} - 560) q^{52} + (182 \zeta_{6} - 182) q^{61} - 512 q^{64} + 880 \zeta_{6} q^{67} + 1190 q^{73} + 448 \zeta_{6} q^{76} + (884 \zeta_{6} - 884) q^{79} - 1400 q^{91} + ( - 1330 \zeta_{6} + 1330) q^{97} +O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 2 q + 8 q^{4} - 20 q^{7}+O(q^{10}) \) Copy content Toggle raw display \( 2 q + 8 q^{4} - 20 q^{7} + 70 q^{13} - 64 q^{16} + 112 q^{19} + 125 q^{25} - 320 q^{28} - 308 q^{31} + 220 q^{37} + 520 q^{43} - 57 q^{49} - 560 q^{52} - 182 q^{61} - 1024 q^{64} + 880 q^{67} + 2380 q^{73} + 448 q^{76} - 884 q^{79} - 2800 q^{91} + 1330 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/81\mathbb{Z}\right)^\times\).

\(n\) \(2\)
\(\chi(n)\) \(-\zeta_{6}\)

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   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
28.1
0.500000 0.866025i
0.500000 + 0.866025i
0 0 4.00000 6.92820i 0 0 −10.0000 17.3205i 0 0 0
55.1 0 0 4.00000 + 6.92820i 0 0 −10.0000 + 17.3205i 0 0 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
3.b odd 2 1 CM by \(\Q(\sqrt{-3}) \)
9.c even 3 1 inner
9.d odd 6 1 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 81.4.c.b 2
3.b odd 2 1 CM 81.4.c.b 2
9.c even 3 1 9.4.a.a 1
9.c even 3 1 inner 81.4.c.b 2
9.d odd 6 1 9.4.a.a 1
9.d odd 6 1 inner 81.4.c.b 2
36.f odd 6 1 144.4.a.d 1
36.h even 6 1 144.4.a.d 1
45.h odd 6 1 225.4.a.d 1
45.j even 6 1 225.4.a.d 1
45.k odd 12 2 225.4.b.g 2
45.l even 12 2 225.4.b.g 2
63.g even 3 1 441.4.e.i 2
63.h even 3 1 441.4.e.i 2
63.i even 6 1 441.4.e.j 2
63.j odd 6 1 441.4.e.i 2
63.k odd 6 1 441.4.e.j 2
63.l odd 6 1 441.4.a.f 1
63.n odd 6 1 441.4.e.i 2
63.o even 6 1 441.4.a.f 1
63.s even 6 1 441.4.e.j 2
63.t odd 6 1 441.4.e.j 2
72.j odd 6 1 576.4.a.m 1
72.l even 6 1 576.4.a.l 1
72.n even 6 1 576.4.a.m 1
72.p odd 6 1 576.4.a.l 1
99.g even 6 1 1089.4.a.g 1
99.h odd 6 1 1089.4.a.g 1
117.n odd 6 1 1521.4.a.g 1
117.t even 6 1 1521.4.a.g 1
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
9.4.a.a 1 9.c even 3 1
9.4.a.a 1 9.d odd 6 1
81.4.c.b 2 1.a even 1 1 trivial
81.4.c.b 2 3.b odd 2 1 CM
81.4.c.b 2 9.c even 3 1 inner
81.4.c.b 2 9.d odd 6 1 inner
144.4.a.d 1 36.f odd 6 1
144.4.a.d 1 36.h even 6 1
225.4.a.d 1 45.h odd 6 1
225.4.a.d 1 45.j even 6 1
225.4.b.g 2 45.k odd 12 2
225.4.b.g 2 45.l even 12 2
441.4.a.f 1 63.l odd 6 1
441.4.a.f 1 63.o even 6 1
441.4.e.i 2 63.g even 3 1
441.4.e.i 2 63.h even 3 1
441.4.e.i 2 63.j odd 6 1
441.4.e.i 2 63.n odd 6 1
441.4.e.j 2 63.i even 6 1
441.4.e.j 2 63.k odd 6 1
441.4.e.j 2 63.s even 6 1
441.4.e.j 2 63.t odd 6 1
576.4.a.l 1 72.l even 6 1
576.4.a.l 1 72.p odd 6 1
576.4.a.m 1 72.j odd 6 1
576.4.a.m 1 72.n even 6 1
1089.4.a.g 1 99.g even 6 1
1089.4.a.g 1 99.h odd 6 1
1521.4.a.g 1 117.n odd 6 1
1521.4.a.g 1 117.t even 6 1

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{2} \) acting on \(S_{4}^{\mathrm{new}}(81, [\chi])\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{2} \) Copy content Toggle raw display
$3$ \( T^{2} \) Copy content Toggle raw display
$5$ \( T^{2} \) Copy content Toggle raw display
$7$ \( T^{2} + 20T + 400 \) Copy content Toggle raw display
$11$ \( T^{2} \) Copy content Toggle raw display
$13$ \( T^{2} - 70T + 4900 \) Copy content Toggle raw display
$17$ \( T^{2} \) Copy content Toggle raw display
$19$ \( (T - 56)^{2} \) Copy content Toggle raw display
$23$ \( T^{2} \) Copy content Toggle raw display
$29$ \( T^{2} \) Copy content Toggle raw display
$31$ \( T^{2} + 308T + 94864 \) Copy content Toggle raw display
$37$ \( (T - 110)^{2} \) Copy content Toggle raw display
$41$ \( T^{2} \) Copy content Toggle raw display
$43$ \( T^{2} - 520T + 270400 \) Copy content Toggle raw display
$47$ \( T^{2} \) Copy content Toggle raw display
$53$ \( T^{2} \) Copy content Toggle raw display
$59$ \( T^{2} \) Copy content Toggle raw display
$61$ \( T^{2} + 182T + 33124 \) Copy content Toggle raw display
$67$ \( T^{2} - 880T + 774400 \) Copy content Toggle raw display
$71$ \( T^{2} \) Copy content Toggle raw display
$73$ \( (T - 1190)^{2} \) Copy content Toggle raw display
$79$ \( T^{2} + 884T + 781456 \) Copy content Toggle raw display
$83$ \( T^{2} \) Copy content Toggle raw display
$89$ \( T^{2} \) Copy content Toggle raw display
$97$ \( T^{2} - 1330 T + 1768900 \) Copy content Toggle raw display
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