- Commit
- 41a8f18baf8397f546904a2e8c02ceb0d68e20c7
- Parent
- 134990e9507c34cd77dd33b3459f80bb9acd919e
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Added a minor clarification
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Added a minor clarification
1 file changed, 5 insertions, 4 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | sections/complete-reducibility.tex | 9 | 5 | 4 |
diff --git a/sections/complete-reducibility.tex b/sections/complete-reducibility.tex @@ -591,10 +591,11 @@ element of \(\mathcal{U}(\mathfrak{g})\), known as \emph{the Casimir element of a representation}. \begin{definition}\label{def:casimir-element} - Let \(V\) be a finite-dimensional representation of \(\mathfrak{g}\). - Let \(\{X_i\}_i\) be a basis for \(\mathfrak{g}\) and denote by \(\{X^i\}_i\) - its dual basis with respect to the form \(B_V\) -- i.e. the unique basis for - \(\mathfrak{g}\) satisfying \(B_V(X_i, X^j) = \delta_{i j}\). We call + Let \(V\) be a finite-dimensional representation of \(\mathfrak{g}\). Let + \(\{X_i\}_i\) be a basis for \(\mathfrak{g}\) and denote by \(\{X^i\}_i + \subset \mathfrak{g}\) its dual basis with respect to the form \(B_V\) -- + i.e. the unique basis for \(\mathfrak{g}\) satisfying \(B_V(X_i, X^j) = + \delta_{i j}\). We call \[ C_V = X_1 X^1 + \cdots + X_n X^n \in \mathcal{U}(\mathfrak{g}) \]