Properties

Label 18.23.b.a
Level $18$
Weight $23$
Character orbit 18.b
Analytic conductor $55.207$
Analytic rank $0$
Dimension $2$
Inner twists $2$

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Newspace parameters

Copy content comment:Compute space of new eigenforms
 
Copy content gp:[N,k,chi] = [18,23,Mod(17,18)] 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("18.17"); S:= CuspForms(chi, 23); N := Newforms(S);
 
Copy content sage:from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(18, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([1])) N = Newforms(chi, 23, names="a")
 
Level: \( N \) \(=\) \( 18 = 2 \cdot 3^{2} \)
Weight: \( k \) \(=\) \( 23 \)
Character orbit: \([\chi]\) \(=\) 18.b (of order \(2\), degree \(1\), minimal)

Newform invariants

Copy content comment:select newform
 
Copy content sage:traces = [2] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(1)] == traces)
 
Copy content gp:f = lf[1] \\ Warning: the index may be different
 
Self dual: no
Analytic conductor: \(55.2073382715\)
Analytic rank: \(0\)
Dimension: \(2\)
Coefficient field: \(\Q(\sqrt{-2}) \)
Copy content comment:defining polynomial
 
Copy content gp:f.mod \\ as an extension of the character field
 
Defining polynomial: \( x^{2} + 2 \) Copy content Toggle raw display
Coefficient ring: \(\Z[a_1, \ldots, a_{5}]\)
Coefficient ring index: \( 1 \)
Twist minimal: yes
Sato-Tate group: $\mathrm{SU}(2)[C_{2}]$

$q$-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 \(\beta = \sqrt{-2}\). We also show the integral \(q\)-expansion of the trace form.

\(f(q)\) \(=\) \( q + 1024 \beta q^{2} - 2097152 q^{4} + 19826925 \beta q^{5} - 1666948276 q^{7} - 2147483648 \beta q^{8} - 40605542400 q^{10} - 130862199588 \beta q^{11} + 399915433112 q^{13} - 1706955034624 \beta q^{14} + \cdots - 11\!\cdots\!52 \beta q^{98} +O(q^{100}) \) Copy content Toggle raw display
\(\operatorname{Tr}(f)(q)\) \(=\) \( 2 q - 4194304 q^{4} - 3333896552 q^{7} - 81211084800 q^{10} + 799830866224 q^{13} + 8796093022208 q^{16} - 285207622064672 q^{19} + 536011569512448 q^{22} + 31\!\cdots\!50 q^{25} + 69\!\cdots\!04 q^{28}+ \cdots - 10\!\cdots\!32 q^{97}+O(q^{100}) \) Copy content Toggle raw display

Character values

We give the values of \(\chi\) on generators for \(\left(\mathbb{Z}/18\mathbb{Z}\right)^\times\).

\(n\) \(11\)
\(\chi(n)\) \(-1\)

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.

Copy content comment:embeddings in the coefficient field
 
Copy content gp:mfembed(f)
 
Label   \(\iota_m(\nu)\) \( a_{2} \) \( a_{3} \) \( a_{4} \) \( a_{5} \) \( a_{6} \) \( a_{7} \) \( a_{8} \) \( a_{9} \) \( a_{10} \)
17.1
1.41421i
1.41421i
1448.15i 0 −2.09715e6 2.80395e7i 0 −1.66695e9 3.03700e9i 0 −4.06055e10
17.2 1448.15i 0 −2.09715e6 2.80395e7i 0 −1.66695e9 3.03700e9i 0 −4.06055e10
\(n\): 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 inner

Twists

       By twisting character orbit
Char Parity Ord Mult Type Twist Min Dim
1.a even 1 1 trivial 18.23.b.a 2
3.b odd 2 1 inner 18.23.b.a 2
    
        By twisted newform orbit
Twist Min Dim Char Parity Ord Mult Type
18.23.b.a 2 1.a even 1 1 trivial
18.23.b.a 2 3.b odd 2 1 inner

Hecke kernels

This newform subspace can be constructed as the kernel of the linear operator \( T_{5}^{2} + 786213909911250 \) acting on \(S_{23}^{\mathrm{new}}(18, [\chi])\). Copy content Toggle raw display

Hecke characteristic polynomials

$p$ $F_p(T)$
$2$ \( T^{2} + 2097152 \) Copy content Toggle raw display
$3$ \( T^{2} \) Copy content Toggle raw display
$5$ \( T^{2} + 786213909911250 \) Copy content Toggle raw display
$7$ \( (T + 1666948276)^{2} \) Copy content Toggle raw display
$11$ \( T^{2} + 34\!\cdots\!88 \) Copy content Toggle raw display
$13$ \( (T - 399915433112)^{2} \) Copy content Toggle raw display
$17$ \( T^{2} + 26\!\cdots\!02 \) Copy content Toggle raw display
$19$ \( (T + 142603811032336)^{2} \) Copy content Toggle raw display
$23$ \( T^{2} + 20\!\cdots\!08 \) Copy content Toggle raw display
$29$ \( T^{2} + 35\!\cdots\!78 \) Copy content Toggle raw display
$31$ \( (T - 58\!\cdots\!24)^{2} \) Copy content Toggle raw display
$37$ \( (T - 99\!\cdots\!14)^{2} \) Copy content Toggle raw display
$41$ \( T^{2} + 24\!\cdots\!38 \) Copy content Toggle raw display
$43$ \( (T - 84\!\cdots\!80)^{2} \) Copy content Toggle raw display
$47$ \( T^{2} + 55\!\cdots\!00 \) Copy content Toggle raw display
$53$ \( T^{2} + 16\!\cdots\!18 \) Copy content Toggle raw display
$59$ \( T^{2} + 19\!\cdots\!32 \) Copy content Toggle raw display
$61$ \( (T - 64\!\cdots\!50)^{2} \) Copy content Toggle raw display
$67$ \( (T - 20\!\cdots\!72)^{2} \) Copy content Toggle raw display
$71$ \( T^{2} + 52\!\cdots\!12 \) Copy content Toggle raw display
$73$ \( (T - 55\!\cdots\!96)^{2} \) Copy content Toggle raw display
$79$ \( (T + 76\!\cdots\!76)^{2} \) Copy content Toggle raw display
$83$ \( T^{2} + 47\!\cdots\!72 \) Copy content Toggle raw display
$89$ \( T^{2} + 12\!\cdots\!02 \) Copy content Toggle raw display
$97$ \( (T + 52\!\cdots\!16)^{2} \) Copy content Toggle raw display
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