jb2170

[jb2170 @SelfAdjOperator]

A belated happy birthday to Cecil Rhodes! I was so focused on July 4th that the following day slipped my mind.
https://t.co/XxNmnb93R8

[jb2170 @SelfAdjOperator]

@Anthony_Bonato At the top.

[jb2170 @SelfAdjOperator]

@paysmaths Also known as Burnside's Lemma, I did have to check "wait I recognise this" 😅 For G acting on X giving a permutation character χ, evaluating <1,χ> counts the number of orbits of the action. If G acts 2-transitively then χ-1 is thus an irreducible character as <χ,χ>=<1,χ_{XX}>=2