Defining parameters
Level: | \( N \) | \(=\) | \( 4 = 2^{2} \) |
Weight: | \( k \) | \(=\) | \( 18 \) |
Character orbit: | \([\chi]\) | \(=\) | 4.a (trivial) |
Character field: | \(\Q\) | ||
Newform subspaces: | \( 1 \) | ||
Sturm bound: | \(9\) | ||
Trace bound: | \(0\) |
Dimensions
The following table gives the dimensions of various subspaces of \(M_{18}(\Gamma_0(4))\).
Total | New | Old | |
---|---|---|---|
Modular forms | 10 | 2 | 8 |
Cusp forms | 7 | 2 | 5 |
Eisenstein series | 3 | 0 | 3 |
The following table gives the dimensions of the cuspidal new subspaces with specified eigenvalues for the Atkin-Lehner operators and the Fricke involution.
\(2\) | Dim |
---|---|
\(-\) | \(2\) |
Trace form
Decomposition of \(S_{18}^{\mathrm{new}}(\Gamma_0(4))\) into newform subspaces
Label | Dim | $A$ | Field | CM | Traces | A-L signs | $q$-expansion | ||||
---|---|---|---|---|---|---|---|---|---|---|---|
$a_{2}$ | $a_{3}$ | $a_{5}$ | $a_{7}$ | 2 | |||||||
4.18.a.a | $2$ | $7.329$ | \(\Q(\sqrt{9361}) \) | None | \(0\) | \(-5880\) | \(604044\) | \(25350160\) | $-$ | \(q+(-2940-\beta )q^{3}+(302022+6^{2}\beta )q^{5}+\cdots\) |
Decomposition of \(S_{18}^{\mathrm{old}}(\Gamma_0(4))\) into lower level spaces
\( S_{18}^{\mathrm{old}}(\Gamma_0(4)) \cong \) \(S_{18}^{\mathrm{new}}(\Gamma_0(1))\)\(^{\oplus 3}\)\(\oplus\)\(S_{18}^{\mathrm{new}}(\Gamma_0(2))\)\(^{\oplus 2}\)