Space of modular forms of level 27, weight 8, and trivial character

• Label: 27.8.a
• Level: $27$
• Weight: $8$
• Character orbit: 27.a
• Rep. character: $\chi_{27}(1,\cdot)$
• Character field: $\Q$
• Dimension: $9$
• Newform subspaces: $5$
• Sturm bound: $24$
• Trace bound: $4$

Defining parameters

Level:	\( N \)	\(=\)	\( 27 = 3^{3} \)
Weight:	\( k \)	\(=\)	\( 8 \)
Character orbit:	\([\chi]\)	\(=\)	27.a (trivial)
Character field:			\(\Q\)
Newform subspaces:			\( 5 \)
Sturm bound:			\(24\)
Trace bound:			\(4\)
Distinguishing \(T_p\):			\(2\)

Dimensions

The following table gives the dimensions of various subspaces of \(M_{8}(\Gamma_0(27))\).

	Total	New	Old
Modular forms	24	9	15
Cusp forms	18	9	9
Eisenstein series	6	0	6

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

\(3\)	Dim
\(+\)	\(5\)
\(-\)	\(4\)

Trace form

\( 9 q + 486 q^{4} - 477 q^{7} + O(q^{10}) \)

Decomposition of \(S_{8}^{\mathrm{new}}(\Gamma_0(27))\) 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
														$a_{2}$	$a_{3}$	$a_{5}$	$a_{7}$		3
27.8.a.a	$27$	$8$	27.a	1.a	$1$	$1$	$1$	$8.434$	\(\Q\)	\(\Q(\sqrt{-3}) \)	✓	$2$	$0$	\(0\)	\(0\)	\(0\)	\(1763\)		$+$	$+$	$1$	$N(\mathrm{U}(1))$	\(q-2^{7}q^{4}+1763q^{7}+12605q^{13}+\cdots\)
27.8.a.b	$27$	$8$	27.a	1.a	$1$	$2$	$2$	$8.434$	\(\Q(\sqrt{65}) \)	None	✓	$1$	$1$	\(-9\)	\(0\)	\(-180\)	\(700\)		$-$	$-$	$3$	$\mathrm{SU}(2)$	\(q+(-5-\beta )q^{2}+(43+9\beta )q^{4}+(-91+\cdots)q^{5}+\cdots\)
27.8.a.c	$27$	$8$	27.a	1.a	$1$	$2$	$2$	$8.434$	\(\Q(\sqrt{3}) \)	None	✓	$2$	$1$	\(0\)	\(0\)	\(0\)	\(-1118\)		$-$	$-$	$2\cdot 3$	$\mathrm{SU}(2)$	\(q+\beta q^{2}-20q^{4}-34\beta q^{5}-559q^{7}+\cdots\)
27.8.a.d	$27$	$8$	27.a	1.a	$1$	$2$	$2$	$8.434$	\(\Q(\sqrt{42}) \)	None	✓	$2$	$0$	\(0\)	\(0\)	\(0\)	\(-2522\)		$+$	$+$	$3$	$\mathrm{SU}(2)$	\(q+\beta q^{2}+250q^{4}+20\beta q^{5}-1261q^{7}+\cdots\)
27.8.a.e	$27$	$8$	27.a	1.a	$1$	$2$	$2$	$8.434$	\(\Q(\sqrt{65}) \)	None	✓	$1$	$0$	\(9\)	\(0\)	\(180\)	\(700\)		$+$	$+$	$3$	$\mathrm{SU}(2)$	\(q+(5+\beta )q^{2}+(43+9\beta )q^{4}+(91+2\beta )q^{5}+\cdots\)

Decomposition of \(S_{8}^{\mathrm{old}}(\Gamma_0(27))\) into lower level spaces

\( S_{8}^{\mathrm{old}}(\Gamma_0(27)) \cong \) \(S_{8}^{\mathrm{new}}(\Gamma_0(3))\)\(^{\oplus 3}\)\(\oplus\)\(S_{8}^{\mathrm{new}}(\Gamma_0(9))\)\(^{\oplus 2}\)