Defining parameters
| Level: | \( N \) | = | \( 16 = 2^{4} \) |
| Weight: | \( k \) | = | \( 4 \) |
| Nonzero newspaces: | \( 2 \) | ||
| Newform subspaces: | \( 2 \) | ||
| Sturm bound: | \(64\) | ||
| Trace bound: | \(1\) |
Dimensions
The following table gives the dimensions of various subspaces of \(M_{4}(\Gamma_1(16))\).
| Total | New | Old | |
|---|---|---|---|
| Modular forms | 31 | 16 | 15 |
| Cusp forms | 17 | 11 | 6 |
| Eisenstein series | 14 | 5 | 9 |
Trace form
Decomposition of \(S_{4}^{\mathrm{new}}(\Gamma_1(16))\)
We only show spaces with even parity, since no modular forms exist when this condition is not satisfied. Within each space \( S_k^{\mathrm{new}}(N, \chi) \) we list available newforms together with their dimension.
| Label | \(\chi\) | Newforms | Dimension | \(\chi\) degree |
|---|---|---|---|---|
| 16.4.a | \(\chi_{16}(1, \cdot)\) | 16.4.a.a | 1 | 1 |
| 16.4.b | \(\chi_{16}(9, \cdot)\) | None | 0 | 1 |
| 16.4.e | \(\chi_{16}(5, \cdot)\) | 16.4.e.a | 10 | 2 |
Decomposition of \(S_{4}^{\mathrm{old}}(\Gamma_1(16))\) into lower level spaces
\( S_{4}^{\mathrm{old}}(\Gamma_1(16)) \cong \) \(S_{4}^{\mathrm{new}}(\Gamma_1(1))\)\(^{\oplus 5}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(2))\)\(^{\oplus 4}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(4))\)\(^{\oplus 3}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(8))\)\(^{\oplus 2}\)