Difference between revisions of "M(8,5,3)"

From Block library
Jump to: navigation, search
(Decomposition and Cartan corrected)
(Added PIMs)
Line 1: Line 1:
 
{{blockbox
 
{{blockbox
 
|title = M(8,5,3) - <math>k(A_4 \times C_2)</math>  
 
|title = M(8,5,3) - <math>k(A_4 \times C_2)</math>  
|image =  
+
|image = M(8,5,3)quiver.png
 
|representative =  <math>k(A_4 \times C_2)</math>
 
|representative =  <math>k(A_4 \times C_2)</math>
 
|defect = [[C2xC2xC2|<math>C_2 \times C_2 \times C_2</math>]]
 
|defect = [[C2xC2xC2|<math>C_2 \times C_2 \times C_2</math>]]
Line 52: Line 52:
 
== Projective indecomposable modules ==
 
== 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}{ccc}
 +
    & S_1 & \\
 +
    S_1 & S_2 & S_3 \\
 +
    S_2 & S_3 & S_1 \\ 
 +
    & S_1 & \\
 +
  \end{array},
 +
&
 +
  \begin{array}{ccc}
 +
    & S_2 & \\
 +
    S_1 & S_3 & S_2 \\
 +
    S_2 & S_1 & S_3 \\
 +
    & S_2 & \\
 +
  \end{array}, 
 +
&
 +
  \begin{array}{ccc}
 +
    & S_3 & \\
 +
    S_1 & S_2 & S_3 \\
 +
    S_3 & S_1 & S_2 \\
 +
    & S_3 & \\
 +
  \end{array}
 +
\end{array}
 +
</math>
  
 
== Irreducible characters ==
 
== Irreducible characters ==

Revision as of 08:39, 9 September 2018

M(8,5,3) - [math]k(A_4 \times C_2)[/math]
M(8,5,3)quiver.png
Representative: [math]k(A_4 \times C_2)[/math]
Defect groups: [math]C_2 \times C_2 \times C_2[/math]
Inertial quotients: [math]1[/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} 4 & 2 & 2 \\ 2 & 4 & 2 \\ 2 & 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]\mathcal{O} (A_4 \times C_2)[/math]
Decomposition matrices: [math]\left( \begin{array}{ccc} 1 & 0 & 0 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \\ 0 & 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]PI(B)=[/math] {{{PIgroup}}}
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: {{{coveringblocks}}}
[math]p'[/math]-index covered blocks: {{{coveredblocks}}}
Index [math]p[/math] covering blocks: {{{pcoveringblocks}}}


Basic algebra

Quiver: a:<1,2>, b:<2,3>, c:<3,1>, d:<2,1>, e:<3,2>, f: <1,3>, g:<1,1>, h:<2,2>, i:<3,3>


Relations w.r.t. [math]k[/math]: ab=bc=ca=0, df=fe=ed=0, ad=fc, be=da, cf=eb, g^2=h^2=i^2=0, ah=ga, bi=hb, cg=ic, dg=hd, eh=ie, fi=gf

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}{ccc} & S_1 & \\ S_1 & S_2 & S_3 \\ S_2 & S_3 & S_1 \\ & S_1 & \\ \end{array}, & \begin{array}{ccc} & S_2 & \\ S_1 & S_3 & S_2 \\ S_2 & S_1 & S_3 \\ & S_2 & \\ \end{array}, & \begin{array}{ccc} & S_3 & \\ S_1 & S_2 & S_3 \\ S_3 & S_1 & S_2 \\ & 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]