M(16,14,3)

M(16,14,2) - [math]k(C_2 \times C_2 \times A_4)[/math]

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Representative:	[math]k(C_2 \times C_2 \times A_4)[/math]
Defect groups:	[math](C_2)^4[/math]
Inertial quotients:	[math]C_3[/math]
[math]k(B)=[/math]	16
[math]l(B)=[/math]	3
[math]{\rm mf}_k(B)=[/math]	1
[math]{\rm Pic}_k(B)=[/math]
Cartan matrix:	[math]\left( \begin{array}{ccc} 8 & 4 & 4\\ 4 & 8 & 4 \\ 4 & 4 & 8 \end{array} \right)[/math]
Defect group Morita invariant?	Yes
Inertial quotient Morita invariant?	Yes
[math]\mathcal{O}[/math]-Morita classes known?	Yes
[math]\mathcal{O}[/math]-Morita classes:	[math]B_0(\mathcal{O} (C_2 \times C_2 \times A_4)[/math]
Decomposition matrices:	See below
[math]{\rm mf}_\mathcal{O}(B)=[/math]	1
[math]{\rm Pic}_{\mathcal{O}}(B)=[/math]	[math](C_2 \times C_2):S_3 \times S_3[/math]
[math]PI(B)=[/math]
Source algebras known?	No
Source algebra reps:
[math]k[/math]-derived equiv. classes known?	Yes
[math]k[/math]-derived equivalent to:	M(16,14,2)
[math]\mathcal{O}[/math]-derived equiv. classes known?	Yes
[math]p'[/math]-index covering blocks:
[math]p'[/math]-index covered blocks:
Index [math]p[/math] covering blocks:

Covering blocks and covered blocks

Let [math]N \triangleleft G[/math] with [math]p'[/math]-index and let [math]B[/math] be a block of [math]\mathcal{O} G[/math] covering a block [math]b[/math] of [math]\mathcal{O} N[/math].

If [math]b[/math] is in M(16,14,3), then [math]B[/math] is in M(16,14,1), M(16,14,3), M(16,14,8), M(16,14,16).

Projective indecomposable modules

Labelling the simple [math]B[/math]-modules by [math]S_1, S_2, S_3[/math], the projective indecomposable modules have Loewy structure as follows:

[math]\begin{array}{ccc} \begin{array}{c} S_1 \\ S_1 S_1 S_2 S_3 \\ S_1 S_1 S_2 S_2 S_3 S_3 \\ S_1 S_1 S_2 S_3 \\ S_1 \\ \end{array} & \begin{array}{c} S_2 \\ S_1 S_2 S_2 S_3 \\ S_1 S_1 S_2 S_2 S_3 S_3 \\ S_1 S_2 S_2 S_3 \\ S_2 \\ \end{array} & \begin{array}{c} S_3 \\ S_1 S_2 S_3 S_3 \\ S_1 S_1 S_2 S_2 S_3 S_3 \\ S_1 S_2 S_3 S_3 \\ S_3 \\ \end{array} \end{array} [/math]

Irreducible characters

All irreducible characters have height zero.

Decomposition matrix

[math]\left( \begin{array}{ccc} 1 &0 &0 \\ 1 &0 &0 \\ 1 &0 &0 \\ 1 &0 &0 \\ 0 &0 &1 \\ 0 &1 &0 \\ 0 &0 &1 \\ 0 &1 &0 \\ 0 &0 &1 \\ 0 &1 &0 \\ 0 &0 &1 \\ 0 &1 &0 \\ 1 &1 &1 \\ 1 &1 &1 \\ 1 &1 &1 \\ 1 &1 &1 \end{array}\right)[/math]

Back to [math](C_2)^4[/math]