Defining parameters
| Level: | \( N \) | \(=\) | \( 91 = 7 \cdot 13 \) |
| Weight: | \( k \) | \(=\) | \( 4 \) |
| Character orbit: | \([\chi]\) | \(=\) | 91.e (of order \(3\) and degree \(2\)) |
| Character conductor: | \(\operatorname{cond}(\chi)\) | \(=\) | \( 7 \) |
| Character field: | \(\Q(\zeta_{3})\) | ||
| Newform subspaces: | \( 2 \) | ||
| Sturm bound: | \(37\) | ||
| Trace bound: | \(1\) | ||
| Distinguishing \(T_p\): | \(2\) |
Dimensions
The following table gives the dimensions of various subspaces of \(M_{4}(91, [\chi])\).
| Total | New | Old | |
|---|---|---|---|
| Modular forms | 60 | 48 | 12 |
| Cusp forms | 52 | 48 | 4 |
| Eisenstein series | 8 | 0 | 8 |
Trace form
Decomposition of \(S_{4}^{\mathrm{new}}(91, [\chi])\) into newform subspaces
| Label | Dim | $A$ | Field | CM | Traces | $q$-expansion | |||
|---|---|---|---|---|---|---|---|---|---|
| $a_{2}$ | $a_{3}$ | $a_{5}$ | $a_{7}$ | ||||||
| 91.4.e.a | $22$ | $5.369$ | None | \(7\) | \(0\) | \(-2\) | \(28\) | ||
| 91.4.e.b | $26$ | $5.369$ | None | \(-5\) | \(0\) | \(14\) | \(-20\) | ||
Decomposition of \(S_{4}^{\mathrm{old}}(91, [\chi])\) into lower level spaces
\( S_{4}^{\mathrm{old}}(91, [\chi]) \simeq \) \(S_{4}^{\mathrm{new}}(7, [\chi])\)\(^{\oplus 2}\)