Difference between revisions of "Blocks with basic algebras of low dimension"
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− | == Blocks with basic algebras of dimension at most | + | == Blocks with basic algebras of dimension at most 16 == |
− | In [[References#L|[Li18b]]] Markus Linckelmann calculated the <math>k</math>-algebras of dimension at most twelve which occur as basic algebras of blocks of finite groups, with the exception of one case of dimension 9 where no block with that basic algebra was identified | + | In [[References#L|[Li18b]]] Markus Linckelmann calculated the <math>k</math>-algebras of dimension at most twelve which occur as basic algebras of blocks of finite groups, with the exception of one case of dimension 9 where no block with that basic algebra was identified. This final case was ruled out by Linckelmann and Murphy in [[References#L|[LM20]]]. Using the classification of finite simple groups, the basic algebras of dimension 13 or 14 for blocks of finite groups were calculated by Sambale in [[References#S|[Sa20]]]. Later Benson and Sambale in [[References#B|[BS23]]] gave a classification for dimensions 15 and 16, except for one unsettled case of a block with defect group <math>C_{13}</math> in dimension 15. |
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The results are incorporated into the table below. | The results are incorporated into the table below. | ||
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| 15 || M(19,1,?) || <math>C_{19}</math> || <math>B_0(kGL_3(7))</math> || || | | 15 || M(19,1,?) || <math>C_{19}</math> || <math>B_0(kGL_3(7))</math> || || | ||
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− | | 15 || || <math>C_{13}</math> || ?? || || | + | | 15 || || <math>C_{13}</math> || ?? || || || |
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Latest revision as of 13:33, 13 December 2023
Blocks with basic algebras of dimension at most 16
In [Li18b] Markus Linckelmann calculated the [math]k[/math]-algebras of dimension at most twelve which occur as basic algebras of blocks of finite groups, with the exception of one case of dimension 9 where no block with that basic algebra was identified. This final case was ruled out by Linckelmann and Murphy in [LM20]. Using the classification of finite simple groups, the basic algebras of dimension 13 or 14 for blocks of finite groups were calculated by Sambale in [Sa20]. Later Benson and Sambale in [BS23] gave a classification for dimensions 15 and 16, except for one unsettled case of a block with defect group [math]C_{13}[/math] in dimension 15.
The results are incorporated into the table below.
Dimension | Class | Defect group | Representative | [math]\dim_k(Z(A))[/math] | [math]l(A)[/math] | Notes |
---|---|---|---|---|---|---|
1 | M(1,1,1) | [math]1[/math] | [math]k1[/math] | 1 | 1 | Blocks of defect zero |
2 | M(2,1,1) | [math]C_2[/math] | [math]kC_2[/math] | 2 | 1 | |
3 | M(3,1,1) | [math]C_3[/math] | [math]kC_3[/math] | 3 | 1 | |
4 | M(4,1,1) | [math]C_4[/math] | [math]kC_4[/math] | 4 | 1 | |
4 | M(4,2,1) | [math]C_2 \times C_2[/math] | [math]k(C_2 \times C_2)[/math] | 4 | 1 | |
5 | M(5,1,1) | [math]C_5[/math] | [math]kC_5[/math] | 5 | 1 | |
6 | M(3,1,2) | [math]C_3[/math] | [math]kS_3[/math] | 3 | 2 | |
7 | M(5,1,3) | [math]C_5[/math] | [math]B_0(kA_5)[/math] | 4 | 2 | |
7 | M(7,1,1) | [math]C_7[/math] | [math]kC_7[/math] | 7 | 1 | |
8 | M(8,1,1) | [math]C_8[/math] | [math]kC_8[/math] | 8 | 1 | |
8 | M(8,2,1) | [math]C_4 \times C_2[/math] | [math]k(C_4 \times C_2)[/math] | 8 | 1 | |
8 | M(8,3,1) | [math]D_8[/math] | [math]kD_8[/math] | 5 | 1 | |
8 | M(8,4,1) | [math]Q_8[/math] | [math]kQ_8[/math] | 5 | 1 | |
8 | M(8,5,1) | [math]C_2 \times C_2 \times C_2[/math] | [math]k(C_2 \times C_2 \times C_2)[/math] | 8 | 1 | |
8 | M(7,1,3) | [math]C_7[/math] | [math]B_0(kPSL_2(13))[/math] | 5 | 2 | |
9 | M(9,1,1) | [math]C_9[/math] | [math]kC_9[/math] | 9 | 1 | |
9 | M(9,1,3) | [math]C_9[/math] | [math]B_0(kSL_2(8))[/math] | 6 | 2 | |
9 | M(9,2,1) | [math]C_3 \times C_3[/math] | [math]k(C_3 \times C_3)[/math] | 9 | 1 | |
9 | M(9,2,23) | [math]C_3 \times C_3[/math] | Faithful block of [math]k((C_3 \times C_3):Q_8)[/math], in which [math]Z(Q_8)[/math] acts trivially | 6 | 1 | SmallGroup(72,24) |
10 | M(5,1,2) | [math]C_5[/math] | [math]kD_{10}[/math] | 4 | 2 | |
10 | M(11,1,3) | [math]C_{11}[/math] | [math]B_0(kSL_2(32))[/math] | 7 | 2 | |
11 | M(8,3,3) | [math]D_8[/math] | [math]kS_4[/math] | 5 | 2 | |
11 | M(7,1,6) | [math]C_7[/math] | [math]B_0(kA_7)[/math] | 5 | 3 | |
11 | M(11,1,1) | [math]C_{11}[/math] | [math]kC_{11}[/math] | 11 | 1 | |
11 | M(13,1,3) | [math]C_{13}[/math] | [math]B_0(kPSL_2(25))[/math] | 8 | 2 | |
12 | M(4,2,3) | [math]C_2 \times C_2[/math] | [math]kA_4[/math] | 4 | 3 | |
13 | M(16,7,3) | [math]D_{16}[/math] | [math]B_0(kPGL_2(7))[/math] | 7 | 2 | |
13 | M(16,8,4) | [math]SD_{16}[/math] | [math]B_3(k(3.M_{10}))[/math] | 7 | 2 | |
13 | M(7,1,7) | [math]C_7[/math] | [math]B_{15}(k6.A_7)[/math] | 5 | 3 | |
13 | M(13,1,1) | [math]C_{13}[/math] | [math]kC_{13}[/math] | 13 | 1 | |
13 | M(13,1,?) | [math]C_{13}[/math] | [math]B_0(kPSL_3(3))[/math] | 7 | 3 | |
13 | M(17,1,?) | [math]C_{17}[/math] | [math]B_0(kPSL_2(16))[/math] | 10 | 2 | |
14 | M(5,1,5) | [math]C_5[/math] | [math]B_0(kS_5)[/math] | 5 | 4 | |
14 | M(7,1,2) | [math]C_7[/math] | [math]kD_{14}[/math] | 5 | 2 | |
14 | M(7,1,5) | [math]C_7[/math] | [math]B_0(kPSL_3(3))[/math] | 5 | 3 | |
14 | M(19,1,?) | [math]C_{19}[/math] | [math]B_0(kPSL_2(37))[/math] | 11 | 2 | |
15 | M(19,1,?) | [math]C_{19}[/math] | [math]B_0(kGL_3(7))[/math] | |||
15 | [math]C_{13}[/math] | ?? |