Difference between revisions of "M(9,2,3)"
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Revision as of 20:20, 22 October 2018
Representative: | [math]k((C_3 \times C_3):C_2)[/math] |
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Defect groups: | [math]C_3 \times C_3[/math] |
Inertial quotients: | [math]C_2[/math] |
[math]k(B)=[/math] | 9 |
[math]l(B)=[/math] | 2 |
[math]{\rm mf}_k(B)=[/math] | 1 |
[math]{\rm Pic}_k(B)=[/math] | |
Cartan matrix: | [math]\left( \begin{array}{cc} 5 & 4 \\ 4 & 5 \\ \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]\mathcal{O} ((C_3 \times C_3):C_2)[/math] |
Decomposition matrices: | [math]\left( \begin{array}{cc} 1 & 0 \\ 0 & 1 \\ 1 & 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[/math][1] |
[math]PI(B)=[/math] | |
Source algebras known? | No |
Source algebra reps: | |
[math]k[/math]-derived equiv. classes known? | No |
[math]k[/math]-derived equivalent to: | none known |
[math]\mathcal{O}[/math]-derived equiv. classes known? | No |
[math]p'[/math]-index covering blocks: | |
[math]p'[/math]-index covered blocks: | |
Index [math]p[/math] covering blocks: |
The representative [math]k((C_3 \times C_3):C_2)[/math] is given by [math]C_3 \times C_3[/math] acted on by an element inverting those of [math]C_3 \times C_3[/math], i.e., it is the group SmallGroup(18,4).
Contents
Basic algebra
Quiver: a:<1,2>, b:<1,2>, c:<2,1>, d:<2,1>
Relations w.r.t. [math]k[/math]: [math]ad=bc[/math], [math]cb=da[/math], [math]aca=bdb=0[/math], [math]cac=dbd=0[/math]
Other notatable representatives
Covering blocks and covered blocks
Projective indecomposable modules
Labelling the unique simple [math]B[/math]-module by [math]1,2[/math], the projective indecomposable modules have Loewy structure as follows:
[math]\begin{array}{cc} \begin{array}{ccccc} & & 1 & & \\ & 2 & & 2 & \\ 1 & & 1 & & 1 \\ & 2 & & 2 & \\ & & 1 & & \\ \end{array}, & \begin{array}{ccccc} & & 2 & & \\ & 1 & & 1 & \\ 2 & & 2 & & 2 \\ & 1 & & 1 & \\ & & 2 & & \\ \end{array} \\ \end{array} [/math]
Irreducible characters
All irreducible characters have height zero.
Back to [math]C_3 \times C_3[/math]