C(3^n)
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Blocks with defect group [math]C_{3^n}[/math]
These are blocks with cyclic defect groups and so they are described by Brauer trees.
For each [math]n\gt 1[/math] there are three [math]\mathcal{O}[/math]-Morita equivalence classes, accounting for all the possible Brauer trees. For [math]n=1[/math] there are just two Morita equivalence classes (see C3).
In the following [math]q_n[/math] is a prime power such that [math](q_n+1)_3=3^n[/math]. For example take [math]q_n=2^{3^{n-1}}[/math].
Class | Representative | [math]k(B)[/math] | [math]l(B)[/math] | Inertial quotients | [math]{\rm Pic}_\mathcal{O}(B)[/math] | [math]{\rm Pic}_k(B)[/math] | [math]{\rm mf_\mathcal{O}(B)}[/math] | [math]{\rm mf_k(B)}[/math] | Notes |
---|---|---|---|---|---|---|---|---|---|
M([math]3^n[/math],1,1) | [math]kC_{3^n}[/math] | [math]3^n[/math] | 1 | [math]1[/math] | [math]C_{3^n} : C_{2.3^{n-1}}[/math] | 1 | 1 | ||
M([math]3^n[/math],1,2) | [math]kD_{2.3^n}[/math] | [math]\frac{(3^n+3)}{2}[/math] | 2 | [math]C_2[/math] | 1 | 1 | |||
M([math]3^n[/math],1,3) | [math]B_0(kPSL_2(q_n))[/math] | [math]\frac{(3^n+3)}{2}[/math] | 2 | [math]C_2[/math] | 1 | 1 |
Blocks in M([math]3^n[/math],1,2) are derived equivalent (over [math]\mathcal{O}[/math]) to those in M([math]3^n[/math],1,3).