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		<id>http://wiki.manchester.ac.uk/blocks/index.php?action=history&amp;feed=atom&amp;title=M%289%2C2%2C1%29</id>
		<title>M(9,2,1) - Revision history</title>
		<link rel="self" type="application/atom+xml" href="http://wiki.manchester.ac.uk/blocks/index.php?action=history&amp;feed=atom&amp;title=M%289%2C2%2C1%29"/>
		<link rel="alternate" type="text/html" href="http://wiki.manchester.ac.uk/blocks/index.php?title=M(9,2,1)&amp;action=history"/>
		<updated>2026-04-23T19:34:37Z</updated>
		<subtitle>Revision history for this page on the wiki</subtitle>
		<generator>MediaWiki 1.30.1</generator>

	<entry>
		<id>http://wiki.manchester.ac.uk/blocks/index.php?title=M(9,2,1)&amp;diff=614&amp;oldid=prev</id>
		<title>Charles Eaton at 17:16, 21 October 2018</title>
		<link rel="alternate" type="text/html" href="http://wiki.manchester.ac.uk/blocks/index.php?title=M(9,2,1)&amp;diff=614&amp;oldid=prev"/>
				<updated>2018-10-21T17:16:47Z</updated>
		
		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr style=&quot;vertical-align: top;&quot; lang=&quot;en-GB&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: white; color:black; text-align: center;&quot;&gt;Revision as of 17:16, 21 October 2018&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l3&quot; &gt;Line 3:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 3:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|image = M(4,2,1)quiver.png&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|image = M(4,2,1)quiver.png&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|representative =&amp;#160; &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|representative =&amp;#160; &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|defect = &amp;lt;math&amp;gt;C_3 \times C_3&amp;lt;/math&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|defect = &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;[[C3xC3|&lt;/ins&gt;&amp;lt;math&amp;gt;C_3 \times C_3&amp;lt;/math&amp;gt;&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|inertialquotients = &amp;lt;math&amp;gt;1&amp;lt;/math&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|inertialquotients = &amp;lt;math&amp;gt;1&amp;lt;/math&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|k(B) = 9&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;|k(B) = 9&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l63&quot; &gt;Line 63:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 63:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;All irreducible characters have height zero.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;&amp;#160;&lt;/td&gt;&lt;td style=&quot;background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;All irreducible characters have height zero.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt;&amp;#160;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[C3xC3|Back to &amp;lt;math&amp;gt;C_3 \times C_3&amp;lt;/math&amp;gt;]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key wki_blocks:diff:version:1.11a:oldid:613:newid:614 --&gt;
&lt;/table&gt;</summary>
		<author><name>Charles Eaton</name></author>	</entry>

	<entry>
		<id>http://wiki.manchester.ac.uk/blocks/index.php?title=M(9,2,1)&amp;diff=613&amp;oldid=prev</id>
		<title>Charles Eaton: Created page with &quot;{{blockbox |title = M(9,2,1) - &lt;math&gt;k(C_3 \times C_3)&lt;/math&gt;  |image = M(4,2,1)quiver.png |representative =  &lt;math&gt;k(C_3 \times C_3)&lt;/math&gt; |defect = &lt;math&gt;C_3 \times C_3&lt;/ma...&quot;</title>
		<link rel="alternate" type="text/html" href="http://wiki.manchester.ac.uk/blocks/index.php?title=M(9,2,1)&amp;diff=613&amp;oldid=prev"/>
				<updated>2018-10-21T17:11:01Z</updated>
		
		<summary type="html">&lt;p&gt;Created page with &amp;quot;{{blockbox |title = M(9,2,1) - &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt;  |image = M(4,2,1)quiver.png |representative =  &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt; |defect = &amp;lt;math&amp;gt;C_3 \times C_3&amp;lt;/ma...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{blockbox&lt;br /&gt;
|title = M(9,2,1) - &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt; &lt;br /&gt;
|image = M(4,2,1)quiver.png&lt;br /&gt;
|representative =  &amp;lt;math&amp;gt;k(C_3 \times C_3)&amp;lt;/math&amp;gt;&lt;br /&gt;
|defect = &amp;lt;math&amp;gt;C_3 \times C_3&amp;lt;/math&amp;gt;&lt;br /&gt;
|inertialquotients = &amp;lt;math&amp;gt;1&amp;lt;/math&amp;gt;&lt;br /&gt;
|k(B) = 9&lt;br /&gt;
|l(B) = 1&lt;br /&gt;
|k-morita-frob = 1 &lt;br /&gt;
|Pic-k= &lt;br /&gt;
|cartan = &amp;lt;math&amp;gt;\left( \begin{array}{c}&lt;br /&gt;
9 \\&lt;br /&gt;
\end{array} \right)&amp;lt;/math&amp;gt;&lt;br /&gt;
|defect-morita-inv? = Yes&lt;br /&gt;
|inertial-morita-inv? = Yes&lt;br /&gt;
|O-morita? = Yes&lt;br /&gt;
|O-morita = &amp;lt;math&amp;gt;\mathcal{O} (C_3 \times C_3)&amp;lt;/math&amp;gt;&lt;br /&gt;
|decomp = &amp;lt;math&amp;gt;\left( \begin{array}{c}&lt;br /&gt;
1 \\&lt;br /&gt;
1 \\&lt;br /&gt;
\vdots \\&lt;br /&gt;
1 \\&lt;br /&gt;
\end{array}\right)&amp;lt;/math&amp;gt;&lt;br /&gt;
|O-morita-frob = 1&lt;br /&gt;
|Pic-O = &amp;lt;math&amp;gt;\mathcal{L}(B)=(C_3 \times C_3):GL_2(3)&amp;lt;/math&amp;gt;&lt;br /&gt;
|PIgroup = &lt;br /&gt;
|source? = No&lt;br /&gt;
|sourcereps =&lt;br /&gt;
|k-derived-known? = Yes&lt;br /&gt;
|k-derived = Forms a derived equivalence class&lt;br /&gt;
|O-derived-known? = Yes&lt;br /&gt;
|coveringblocks = [[M(9,2,2)]], [[M(9,2,3)]] (complete)&lt;br /&gt;
|coveredblocks = &lt;br /&gt;
|pcoveringblocks = [[M(27,2,1)]], [[M(27,5,1)]]&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
These are [[Nilpotent blocks|nilpotent blocks]].&lt;br /&gt;
&lt;br /&gt;
== Basic algebra ==&lt;br /&gt;
&lt;br /&gt;
'''Quiver:''' a:&amp;lt;1,1&amp;gt;, b:&amp;lt;1,1&amp;gt;&lt;br /&gt;
&lt;br /&gt;
'''Relations w.r.t. &amp;lt;math&amp;gt;k&amp;lt;/math&amp;gt;:''' a^3=b^3=ab-ba=0&lt;br /&gt;
&lt;br /&gt;
== Other notatable representatives ==&lt;br /&gt;
&lt;br /&gt;
== Covering blocks and covered blocks ==&lt;br /&gt;
&lt;br /&gt;
== Projective indecomposable modules ==&lt;br /&gt;
&lt;br /&gt;
Labelling the unique simple &amp;lt;math&amp;gt;B&amp;lt;/math&amp;gt;-module by &amp;lt;math&amp;gt;1&amp;lt;/math&amp;gt;, the unique projective indecomposable module has Loewy structure as follows:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;\begin{array}{ccccc}&lt;br /&gt;
     &amp;amp; &amp;amp; 1 &amp;amp; &amp;amp; \\&lt;br /&gt;
     &amp;amp; 1 &amp;amp; &amp;amp; 1 &amp;amp; \\&lt;br /&gt;
    1 &amp;amp; &amp;amp; 1 &amp;amp; &amp;amp; 1 \\&lt;br /&gt;
  &amp;amp; 1 &amp;amp; &amp;amp; 1 &amp;amp; \\&lt;br /&gt;
 &amp;amp; &amp;amp; 1 &amp;amp; &amp;amp; \\&lt;br /&gt;
   \end{array}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Irreducible characters ==&lt;br /&gt;
&lt;br /&gt;
All irreducible characters have height zero.&lt;/div&gt;</summary>
		<author><name>Charles Eaton</name></author>	</entry>

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