Properties

Label 28.8.a.b
Level $28$
Weight $8$
Character orbit 28.a
Self dual yes
Analytic conductor $8.747$
Analytic rank $1$
Dimension $2$
CM no
Inner twists $1$

Related objects

Downloads

Learn more

Show commands: Magma / PariGP / SageMath

Newspace parameters

comment: Compute space of new eigenforms
 
[N,k,chi] = [28,8,Mod(1,28)]
 
mf = mfinit([N,k,chi],0)
 
lf = mfeigenbasis(mf)
 
from sage.modular.dirichlet import DirichletCharacter
 
H = DirichletGroup(28, 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("28.1");
 
S:= CuspForms(chi, 8);
 
N := Newforms(S);
 
Level: \( N \) \(=\) \( 28 = 2^{2} \cdot 7 \)
Weight: \( k \) \(=\) \( 8 \)
Character orbit: \([\chi]\) \(=\) 28.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: \(8.74678071356\)
Analytic rank: \(1\)
Dimension: \(2\)
Coefficient field: \(\Q(\sqrt{1009}) \)
comment: defining polynomial
 
gp: f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{2} - x - 252 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, a_2, a_3]\)
Coefficient ring index: \( 2 \)
Twist minimal: yes
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 \(\beta = \sqrt{1009}\). We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + ( - \beta + 7) q^{3} + (11 \beta - 147) q^{5} - 343 q^{7} + ( - 14 \beta - 1129) q^{9} + ( - 182 \beta - 1746) q^{11} + (201 \beta - 8085) q^{13} + (224 \beta - 12128) q^{15} + (382 \beta - 14616) q^{17}+ \cdots + (229922 \beta + 4542166) q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 2 q + 14 q^{3} - 294 q^{5} - 686 q^{7} - 2258 q^{9} - 3492 q^{11} - 16170 q^{13} - 24256 q^{15} - 29232 q^{17} - 3206 q^{19} - 4802 q^{21} - 9360 q^{23} + 131146 q^{25} - 18172 q^{27} + 184704 q^{29} + 165060 q^{31}+ \cdots + 9084332 q^{99}+O(q^{100}) \) 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
16.3824
−15.3824
0 −24.7648 0 202.412 0 −343.000 0 −1573.71 0
1.2 0 38.7648 0 −496.412 0 −343.000 0 −684.293 0
\(n\): e.g. 2-40 or 990-1000
Significant digits:
Format:

Atkin-Lehner signs

\( p \) Sign
\(2\) \( -1 \)
\(7\) \( +1 \)

Inner twists

This newform does not admit any (nontrivial) inner twists.

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 28.8.a.b 2
3.b odd 2 1 252.8.a.f 2
4.b odd 2 1 112.8.a.h 2
7.b odd 2 1 196.8.a.a 2
7.c even 3 2 196.8.e.b 4
7.d odd 6 2 196.8.e.c 4
8.b even 2 1 448.8.a.o 2
8.d odd 2 1 448.8.a.q 2
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
28.8.a.b 2 1.a even 1 1 trivial
112.8.a.h 2 4.b odd 2 1
196.8.a.a 2 7.b odd 2 1
196.8.e.b 4 7.c even 3 2
196.8.e.c 4 7.d odd 6 2
252.8.a.f 2 3.b odd 2 1
448.8.a.o 2 8.b even 2 1
448.8.a.q 2 8.d odd 2 1

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{3}^{2} - 14T_{3} - 960 \) acting on \(S_{8}^{\mathrm{new}}(\Gamma_0(28))\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{2} \) Copy content Toggle raw display
$3$ \( T^{2} - 14T - 960 \) Copy content Toggle raw display
$5$ \( T^{2} + 294T - 100480 \) Copy content Toggle raw display
$7$ \( (T + 343)^{2} \) Copy content Toggle raw display
$11$ \( T^{2} + 3492 T - 30373600 \) Copy content Toggle raw display
$13$ \( T^{2} + 16170 T + 24602616 \) Copy content Toggle raw display
$17$ \( T^{2} + 29232 T + 66390140 \) Copy content Toggle raw display
$19$ \( T^{2} + \cdots - 1457664272 \) Copy content Toggle raw display
$23$ \( T^{2} + 9360 T - 892558336 \) Copy content Toggle raw display
$29$ \( T^{2} + \cdots + 5339156348 \) Copy content Toggle raw display
$31$ \( T^{2} + \cdots - 6660680544 \) Copy content Toggle raw display
$37$ \( T^{2} + \cdots - 45829003940 \) Copy content Toggle raw display
$41$ \( T^{2} + \cdots - 89232832116 \) Copy content Toggle raw display
$43$ \( T^{2} + \cdots - 9812264768 \) Copy content Toggle raw display
$47$ \( T^{2} + \cdots + 216379252512 \) Copy content Toggle raw display
$53$ \( T^{2} + \cdots + 225066151620 \) Copy content Toggle raw display
$59$ \( T^{2} + \cdots + 1833034760000 \) Copy content Toggle raw display
$61$ \( T^{2} + \cdots - 113258778480 \) Copy content Toggle raw display
$67$ \( T^{2} + \cdots - 8822599928240 \) Copy content Toggle raw display
$71$ \( T^{2} + \cdots - 5444851901440 \) Copy content Toggle raw display
$73$ \( T^{2} + \cdots - 19396396395020 \) Copy content Toggle raw display
$79$ \( T^{2} + \cdots + 11938206077568 \) Copy content Toggle raw display
$83$ \( T^{2} + \cdots + 84534867832880 \) Copy content Toggle raw display
$89$ \( T^{2} + \cdots - 12060844881660 \) Copy content Toggle raw display
$97$ \( T^{2} + \cdots + 174783333299356 \) Copy content Toggle raw display
show more
show less