Space of modular forms of level 258, weight 2, and trivial character

• Label: 258.2.a
• Level: $258$
• Weight: $2$
• Character orbit: 258.a
• Rep. character: $\chi_{258}(1,\cdot)$
• Character field: $\Q$
• Dimension: $7$
• Newform subspaces: $7$
• Sturm bound: $88$
• Trace bound: $5$

Defining parameters

Level:	\( N \)	\(=\)	\( 258 = 2 \cdot 3 \cdot 43 \)
Weight:	\( k \)	\(=\)	\( 2 \)
Character orbit:	\([\chi]\)	\(=\)	258.a (trivial)
Character field:			\(\Q\)
Newform subspaces:			\( 7 \)
Sturm bound:			\(88\)
Trace bound:			\(5\)
Distinguishing \(T_p\):			\(5\), \(7\)

Dimensions

The following table gives the dimensions of various subspaces of \(M_{2}(\Gamma_0(258))\).

	Total	New	Old
Modular forms	48	7	41
Cusp forms	41	7	34
Eisenstein series	7	0	7

The following table gives the dimensions of the cuspidal new subspaces with specified eigenvalues for the Atkin-Lehner operators and the Fricke involution.

\(2\)	\(3\)	\(43\)	Fricke	Dim
\(+\)	\(+\)	\(+\)	$+$	\(1\)
\(+\)	\(+\)	\(-\)	$-$	\(1\)
\(+\)	\(-\)	\(-\)	$+$	\(1\)
\(-\)	\(+\)	\(+\)	$-$	\(2\)
\(-\)	\(-\)	\(-\)	$-$	\(2\)
Plus space			\(+\)	\(2\)
Minus space			\(-\)	\(5\)

Trace form

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

Decomposition of \(S_{2}^{\mathrm{new}}(\Gamma_0(258))\) into newform subspaces

Label	Level	Weight	Char	Prim	Char order	Dim	Rel. Dim	$A$	Field	CM	Self-dual	Inner twists	Rank*	Traces					A-L signs			Fricke sign	Coefficient ring index	Sato-Tate	$q$-expansion
														$a_{2}$	$a_{3}$	$a_{5}$	$a_{7}$		2	3	43
258.2.a.a	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$0$	\(-1\)	\(-1\)	\(-2\)	\(2\)		$+$	$+$	$-$	$-$	$1$	$\mathrm{SU}(2)$	\(q-q^{2}-q^{3}+q^{4}-2q^{5}+q^{6}+2q^{7}+\cdots\)
258.2.a.b	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$1$	\(-1\)	\(-1\)	\(1\)	\(-5\)		$+$	$+$	$+$	$+$	$1$	$\mathrm{SU}(2)$	\(q-q^{2}-q^{3}+q^{4}+q^{5}+q^{6}-5q^{7}+\cdots\)
258.2.a.c	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$1$	\(-1\)	\(1\)	\(-3\)	\(-3\)		$+$	$-$	$-$	$+$	$1$	$\mathrm{SU}(2)$	\(q-q^{2}+q^{3}+q^{4}-3q^{5}-q^{6}-3q^{7}+\cdots\)
258.2.a.d	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$0$	\(1\)	\(-1\)	\(-2\)	\(4\)		$-$	$+$	$+$	$-$	$1$	$\mathrm{SU}(2)$	\(q+q^{2}-q^{3}+q^{4}-2q^{5}-q^{6}+4q^{7}+\cdots\)
258.2.a.e	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$0$	\(1\)	\(-1\)	\(3\)	\(-1\)		$-$	$+$	$+$	$-$	$1$	$\mathrm{SU}(2)$	\(q+q^{2}-q^{3}+q^{4}+3q^{5}-q^{6}-q^{7}+\cdots\)
258.2.a.f	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$0$	\(1\)	\(1\)	\(-1\)	\(1\)		$-$	$-$	$-$	$-$	$1$	$\mathrm{SU}(2)$	\(q+q^{2}+q^{3}+q^{4}-q^{5}+q^{6}+q^{7}+\cdots\)
258.2.a.g	$258$	$2$	258.a	1.a	$1$	$1$	$1$	$2.060$	\(\Q\)	None	✓	$1$	$0$	\(1\)	\(1\)	\(2\)	\(-2\)		$-$	$-$	$-$	$-$	$1$	$\mathrm{SU}(2)$	\(q+q^{2}+q^{3}+q^{4}+2q^{5}+q^{6}-2q^{7}+\cdots\)

Decomposition of \(S_{2}^{\mathrm{old}}(\Gamma_0(258))\) into lower level spaces

\( S_{2}^{\mathrm{old}}(\Gamma_0(258)) \cong \) \(S_{2}^{\mathrm{new}}(\Gamma_0(43))\)\(^{\oplus 4}\)\(\oplus\)\(S_{2}^{\mathrm{new}}(\Gamma_0(86))\)\(^{\oplus 2}\)\(\oplus\)\(S_{2}^{\mathrm{new}}(\Gamma_0(129))\)\(^{\oplus 2}\)