Properties

Label 21.8.a.d
Level $21$
Weight $8$
Character orbit 21.a
Self dual yes
Analytic conductor $6.560$
Analytic rank $0$
Dimension $3$
CM no
Inner twists $1$

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Newspace parameters

Copy content comment:Compute space of new eigenforms
 
Copy content gp:[N,k,chi] = [21,8,Mod(1,21)] mf = mfinit([N,k,chi],0) lf = mfeigenbasis(mf)
 
Copy content magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code chi := DirichletCharacter("21.1"); S:= CuspForms(chi, 8); N := Newforms(S);
 
Copy content sage:from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(21, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 0])) N = Newforms(chi, 8, names="a")
 
Level: \( N \) \(=\) \( 21 = 3 \cdot 7 \)
Weight: \( k \) \(=\) \( 8 \)
Character orbit: \([\chi]\) \(=\) 21.a (trivial)

Newform invariants

Copy content comment:select newform
 
Copy content sage:traces = [3,-3] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(2)] == traces)
 
Copy content gp:f = lf[1] \\ Warning: the index may be different
 
Self dual: yes
Analytic conductor: \(6.56008553517\)
Analytic rank: \(0\)
Dimension: \(3\)
Coefficient field: 3.3.2910828.1
Copy content comment:defining polynomial
 
Copy content gp:f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{3} - 303x - 490 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, a_2]\)
Coefficient ring index: \( 2\cdot 3 \)
Twist minimal: yes
Fricke sign: \(+1\)
Sato-Tate group: $\mathrm{SU}(2)$

$q$-expansion

Copy content comment:q-expansion
 
Copy content sage:f.q_expansion() # note that sage often uses an isomorphic number field
 
Copy content gp:mfcoefs(f, 20)
 

Coefficients of the \(q\)-expansion are expressed in terms of a basis \(1,\beta_1,\beta_2\) for the coefficient ring described below. We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + (\beta_1 - 1) q^{2} + 27 q^{3} + (\beta_{2} + 75) q^{4} + ( - 2 \beta_{2} + 16 \beta_1 - 38) q^{5} + (27 \beta_1 - 27) q^{6} + 343 q^{7} + ( - 3 \beta_{2} + 44 \beta_1 + 139) q^{8} + 729 q^{9} + (22 \beta_{2} - 216 \beta_1 + 3098) q^{10}+ \cdots + ( - 7290 \beta_{2} - 116640 \beta_1 + 2122848) q^{99}+O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 3 q - 3 q^{2} + 81 q^{3} + 225 q^{4} - 114 q^{5} - 81 q^{6} + 1029 q^{7} + 417 q^{8} + 2187 q^{9} + 9294 q^{10} + 8736 q^{11} + 6075 q^{12} + 12762 q^{13} - 1029 q^{14} - 3078 q^{15} - 3327 q^{16} + 5490 q^{17}+ \cdots + 6368544 q^{99}+O(q^{100}) \) Copy content Toggle raw display

Basis of coefficient ring in terms of a root \(\nu\) of \( x^{3} - 303x - 490 \) : Copy content Toggle raw display

\(\beta_{1}\)\(=\) \( \nu \) Copy content Toggle raw display
\(\beta_{2}\)\(=\) \( \nu^{2} - 2\nu - 202 \) Copy content Toggle raw display
\(\nu\)\(=\) \( \beta_1 \) Copy content Toggle raw display
\(\nu^{2}\)\(=\) \( \beta_{2} + 2\beta _1 + 202 \) 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.

Copy content comment:embeddings in the coefficient field
 
Copy content 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
−16.5337
−1.63149
18.1652
−17.5337 27.0000 179.431 −511.401 −473.410 343.000 −901.776 729.000 8966.76
1.2 −2.63149 27.0000 −121.075 328.047 −71.0503 343.000 655.440 729.000 −863.253
1.3 17.1652 27.0000 166.644 69.3548 463.461 343.000 663.336 729.000 1190.49
\(n\): e.g. 2-40 or 990-1000
Significant digits:
Format:

Atkin-Lehner signs

\( p \) Sign
\(3\) \( -1 \)
\(7\) \( -1 \)

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 21.8.a.d 3
3.b odd 2 1 63.8.a.g 3
4.b odd 2 1 336.8.a.r 3
5.b even 2 1 525.8.a.g 3
7.b odd 2 1 147.8.a.e 3
7.c even 3 2 147.8.e.i 6
7.d odd 6 2 147.8.e.j 6
21.c even 2 1 441.8.a.n 3
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
21.8.a.d 3 1.a even 1 1 trivial
63.8.a.g 3 3.b odd 2 1
147.8.a.e 3 7.b odd 2 1
147.8.e.i 6 7.c even 3 2
147.8.e.j 6 7.d odd 6 2
336.8.a.r 3 4.b odd 2 1
441.8.a.n 3 21.c even 2 1
525.8.a.g 3 5.b even 2 1

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{2}^{3} + 3T_{2}^{2} - 300T_{2} - 792 \) acting on \(S_{8}^{\mathrm{new}}(\Gamma_0(21))\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{3} + 3 T^{2} + \cdots - 792 \) Copy content Toggle raw display
$3$ \( (T - 27)^{3} \) Copy content Toggle raw display
$5$ \( T^{3} + 114 T^{2} + \cdots + 11635200 \) Copy content Toggle raw display
$7$ \( (T - 343)^{3} \) Copy content Toggle raw display
$11$ \( T^{3} + \cdots + 21104274672 \) Copy content Toggle raw display
$13$ \( T^{3} + \cdots + 755769903784 \) Copy content Toggle raw display
$17$ \( T^{3} + \cdots + 12467114860032 \) Copy content Toggle raw display
$19$ \( T^{3} + \cdots - 5437419408320 \) Copy content Toggle raw display
$23$ \( T^{3} + \cdots - 102906745004448 \) Copy content Toggle raw display
$29$ \( T^{3} + \cdots + 208394349111720 \) Copy content Toggle raw display
$31$ \( T^{3} + \cdots + 24\!\cdots\!64 \) Copy content Toggle raw display
$37$ \( T^{3} + \cdots + 14\!\cdots\!08 \) Copy content Toggle raw display
$41$ \( T^{3} + \cdots + 24\!\cdots\!00 \) Copy content Toggle raw display
$43$ \( T^{3} + \cdots - 30\!\cdots\!36 \) Copy content Toggle raw display
$47$ \( T^{3} + \cdots + 22\!\cdots\!84 \) Copy content Toggle raw display
$53$ \( T^{3} + \cdots + 56\!\cdots\!32 \) Copy content Toggle raw display
$59$ \( T^{3} + \cdots - 31\!\cdots\!00 \) Copy content Toggle raw display
$61$ \( T^{3} + \cdots + 37\!\cdots\!52 \) Copy content Toggle raw display
$67$ \( T^{3} + \cdots - 42\!\cdots\!36 \) Copy content Toggle raw display
$71$ \( T^{3} + \cdots - 56\!\cdots\!08 \) Copy content Toggle raw display
$73$ \( T^{3} + \cdots - 28\!\cdots\!52 \) Copy content Toggle raw display
$79$ \( T^{3} + \cdots + 35\!\cdots\!60 \) Copy content Toggle raw display
$83$ \( T^{3} + \cdots + 79\!\cdots\!52 \) Copy content Toggle raw display
$89$ \( T^{3} + \cdots + 26\!\cdots\!20 \) Copy content Toggle raw display
$97$ \( T^{3} + \cdots + 70\!\cdots\!88 \) Copy content Toggle raw display
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