Defining parameters
Level: | \( N \) | = | \( 5 \) |
Weight: | \( k \) | = | \( 20 \) |
Nonzero newspaces: | \( 2 \) | ||
Newform subspaces: | \( 3 \) | ||
Sturm bound: | \(40\) | ||
Trace bound: | \(1\) |
Dimensions
The following table gives the dimensions of various subspaces of \(M_{20}(\Gamma_1(5))\).
Total | New | Old | |
---|---|---|---|
Modular forms | 21 | 17 | 4 |
Cusp forms | 17 | 15 | 2 |
Eisenstein series | 4 | 2 | 2 |
Trace form
Decomposition of \(S_{20}^{\mathrm{new}}(\Gamma_1(5))\)
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 |
---|---|---|---|---|
5.20.a | \(\chi_{5}(1, \cdot)\) | 5.20.a.a | 3 | 1 |
5.20.a.b | 4 | |||
5.20.b | \(\chi_{5}(4, \cdot)\) | 5.20.b.a | 8 | 1 |
Decomposition of \(S_{20}^{\mathrm{old}}(\Gamma_1(5))\) into lower level spaces
\( S_{20}^{\mathrm{old}}(\Gamma_1(5)) \cong \) \(S_{20}^{\mathrm{new}}(\Gamma_1(1))\)\(^{\oplus 2}\)