diff --git a/Class Notes/Algebra/representation-theory-of-finite-groups.tex b/Class Notes/Algebra/representation-theory-of-finite-groups.tex index 64ae483..5e061ac 100644 --- a/Class Notes/Algebra/representation-theory-of-finite-groups.tex +++ b/Class Notes/Algebra/representation-theory-of-finite-groups.tex @@ -1673,7 +1673,8 @@ \section{Mackey Theory} \tr \rho^3(srs) = \tr \rho^3(r^{-1}) = -1 = \tr \rho^3(r)\), so \(\Ind_{\Z_4}^{D_8} \rho^3\) will \emph{not} be irreducible. On the other hand, one can - check \(\rho^2_s(r) = \rho^2(srs) = \rho^2(r^{-1}) = -i = \rho^4(r)\), so + check \(\tr \rho^2_s(r) = \tr \rho^2(srs) = \tr \rho^2(r^{-1}) = -i + = \tr \rho^4(r)\), so \(\rho^2_s\) and \(\rho^2\) are orthogonal, thus sharing no irreducibles. Thus, it must be that \(\Ind_{\Z_4}^{D_8} \rho^2\) is irreducible. In fact, one can check \(\Ind_{\Z_4}^{D_8} \rho^2 = @@ -1940,7 +1941,7 @@ \section{Example: Representations of the Symmetric Group} \end{ytableau} \] Furthermore, \(\Sym_n\) can act on a Young tableau by permuting the - numbers. So, \((12345)(876)(9,10) \in \Sym_10\) would act on the + numbers. So, \((12345)(876)(9,10) \in \Sym_{10}\) would act on the above diagram to yield \[ \begin{ytableau} 2 & 3 & 4 & 5 & 1\\ @@ -1989,7 +1990,7 @@ \section{Example: Representations of the Symmetric Group} Q(\T) := \sum_{\alpha \in C(\T)} \sgn(\alpha) \alpha \] \end{defn} - +\todo{Finish this to give some idea of irreducibles.} \begin{bibdiv} \begin{biblist} \bib{benson}{book}{