Defining parameters
Level: | \( N \) | = | \( 15 = 3 \cdot 5 \) |
Weight: | \( k \) | = | \( 4 \) |
Nonzero newspaces: | \( 3 \) | ||
Newform subspaces: | \( 4 \) | ||
Sturm bound: | \(64\) | ||
Trace bound: | \(1\) |
Dimensions
The following table gives the dimensions of various subspaces of \(M_{4}(\Gamma_1(15))\).
Total | New | Old | |
---|---|---|---|
Modular forms | 32 | 22 | 10 |
Cusp forms | 16 | 14 | 2 |
Eisenstein series | 16 | 8 | 8 |
Trace form
Decomposition of \(S_{4}^{\mathrm{new}}(\Gamma_1(15))\)
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 |
---|---|---|---|---|
15.4.a | \(\chi_{15}(1, \cdot)\) | 15.4.a.a | 1 | 1 |
15.4.a.b | 1 | |||
15.4.b | \(\chi_{15}(4, \cdot)\) | 15.4.b.a | 4 | 1 |
15.4.e | \(\chi_{15}(2, \cdot)\) | 15.4.e.a | 8 | 2 |
Decomposition of \(S_{4}^{\mathrm{old}}(\Gamma_1(15))\) into lower level spaces
\( S_{4}^{\mathrm{old}}(\Gamma_1(15)) \cong \) \(S_{4}^{\mathrm{new}}(\Gamma_1(1))\)\(^{\oplus 4}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(3))\)\(^{\oplus 2}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(5))\)\(^{\oplus 2}\)\(\oplus\)\(S_{4}^{\mathrm{new}}(\Gamma_1(15))\)\(^{\oplus 1}\)