Past exam of the mathematics course of the University of Cambridge 2018 ii Paper 2 19I b ii Solution Created 2026-09-24 Updated 2026-10-03
The permutation character of a coset action on is . The tensor identity for an induced character therefore givesIf is irreducible, then Frobenius reciprocity givesBoth and are irreducible, so
Past exam of the mathematics course of the University of Cambridge 2019 ii Paper 3 19I b Solution 2026-10-03
On the orbit , an element fixes the coset exactly whenThe character of a representation of the corresponding permutation representation therefore isThis is the permutation character of a coset action.