Space of modular forms of level 91, weight 2, and Character 91.ba

• Label: 91.2.ba
• Level: $91$
• Weight: $2$
• Character orbit: 91.ba
• Rep. character: $\chi_{91}(45,\cdot)$
• Character field: $\Q(\zeta_{12})$
• Dimension: $28$
• Newform subspaces: $1$
• Sturm bound: $18$
• Trace bound: $0$

Defining parameters

Level:	\( N \)	\(=\)	\( 91 = 7 \cdot 13 \)
Weight:	\( k \)	\(=\)	\( 2 \)
Character orbit:	\([\chi]\)	\(=\)	91.ba (of order \(12\) and degree \(4\))
Character conductor:	\(\operatorname{cond}(\chi)\)	\(=\)	\( 91 \)
Character field:			\(\Q(\zeta_{12})\)
Newform subspaces:			\( 1 \)
Sturm bound:			\(18\)
Trace bound:			\(0\)

Dimensions

The following table gives the dimensions of various subspaces of \(M_{2}(91, [\chi])\).

	Total	New	Old
Modular forms	44	44	0
Cusp forms	28	28	0
Eisenstein series	16	16	0

Trace form

\( 28 q - 2 q^{2} - 6 q^{3} - 6 q^{5} - 12 q^{6} - 6 q^{7} - 4 q^{8} + 6 q^{9} + O(q^{10}) \)

Decomposition of \(S_{2}^{\mathrm{new}}(91, [\chi])\) into newform subspaces

Label	Level	Weight	Char	Prim	Char order	Dim	Rel. Dim	$A$	Field	CM	Self-dual	Inner twists	Rank*	Traces				Coefficient ring index	Sato-Tate	$q$-expansion
														$a_{2}$	$a_{3}$	$a_{5}$	$a_{7}$
91.2.ba.a	$91$	$2$	91.ba	91.aa	$12$	$28$	$7$	$0.727$		None		$2$	$0$	\(-2\)	\(-6\)	\(-6\)	\(-6\)		$\mathrm{SU}(2)[C_{12}]$