M(8,5,2)
Representative: | [math]B_0(k(A_5 \times C_2))[/math] |
---|---|
Defect groups: | [math]C_2 \times C_2 \times C_2[/math] |
Inertial quotients: | [math]C_3[/math] |
[math]k(B)=[/math] | 8 |
[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 & 4 & 2 \\ 4 & 2 & 4 \\ \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} (A_5 \times C_2))[/math] |
Decomposition matrices: | [math]\left( \begin{array}{ccc} 1 & 0 & 0 \\ 1 & 0 & 0 \\ 1 & 1 & 0 \\ 1 & 1 & 0 \\ 1 & 0 & 1 \\ 1 & 0 & 1 \\ 1 & 1 & 1 \\ 1 & 1 & 1 \\ \end{array}\right)[/math] |
[math]{\rm mf}_\mathcal{O}(B)=[/math] | 1 |
[math]{\rm Pic}_{\mathcal{O}}(B)=[/math] | [math]C_2 \times C_2[/math][1] |
[math]PI(B)=[/math] | [math]S_4 \times C_2 \times C_2[/math][2] |
Source algebras known? | No |
Source algebra reps: | |
[math]k[/math]-derived equiv. classes known? | Yes |
[math]k[/math]-derived equivalent to: | M(8,5,2) |
[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: |
Contents
Basic algebra
Quiver: a:<1,2>, b:<2,3>, c:<3,2>, d:<2,1>, e:<1,1>, f: <2,2>, g:<3,3>
Relations w.r.t. [math]k[/math]: [math]ad=cb=0[/math], [math]bcda=dabc[/math], [math]e^2=f^2=g^2=0[/math], [math]af=ea[/math], [math]bg=fb[/math], [math]cf=gc[/math], [math]de=fd[/math]
Other notatable representatives
Covering blocks and covered blocks
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_2 S_3 \\ S_2 S_3 S_1 S_1 \\ S_1 S_1 S_3 S_2 \\ S_3 S_2 S_1 \\ S_1 \\ \end{array}, & \begin{array}{c} S_2 \\ S_2 S_1 \\ S_1 S_3 \\ S_3 S_1 \\ S_1 S_2 \\ S_2 \\ \end{array}, & \begin{array}{c} S_3 \\ S_2 S_1 \\ S_1 S_2 \\ S_3 S_1 \\ S_1 S_3 \\ S_3 \end{array} \end{array} [/math]
Irreducible characters
All irreducible characters have height zero.
Back to [math]C_2 \times C_2 \times C_2[/math]- ↑ [math]{\rm Pic}_{\mathcal{O}}(B_0(\mathcal{O}(C_2 \times A_5)))=\mathcal{L}(B_0(\mathcal{O}(C_2 \times A_5)))=\mathcal{L}(\mathcal{O}C_2) \times \mathcal{T}(B_0(\mathcal{O}A_5))[/math] by [EL18c], giving the isomorphism type of [math]{\rm Pic}_\mathcal{O}(B)[/math] in general.
- ↑ By Theorem 3.7 of [EL18c].