- Commit
- 21c5d92c6d3904933cd7605359f1894f16fb8468
- Parent
- c1198935da7cd41892fca822419a34282d80dac5
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Clarified some notation
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Clarified some notation
1 file changed, 9 insertions, 9 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | sections/introduction.tex | 18 | 9 | 9 |
diff --git a/sections/introduction.tex b/sections/introduction.tex @@ -521,15 +521,15 @@ Notice there is a canonical homomorphism \(\mathfrak{g} \to \end{tikzcd} \end{center} -Given \(X, Y \in \mathfrak{g}\), we denote their images under the inclusion -\(\mathfrak{g} \to T \mathfrak{g}\) simply by \(X\) and \(Y\) and we write \(X -\cdot Y\) for \((X \otimes Y) + I\). This notation suggests the map -\(\mathfrak{g} \to \mathcal{U}(\mathfrak{g})\) is injective, but at this point -this is not at all clear -- since the projection \(T \mathfrak{g} \to -\mathcal{U}(\mathfrak{g})\) is not injective. However, we will soon see this is -the case. Intuitively, \(\mathcal{U}(\mathfrak{g})\) is the smallest -associative \(K\)-algebra containing \(\mathfrak{g}\) as a Lie subalgebra. In -practice this means\dots +Given \(X_1, \ldots, X_n \in \mathfrak{g}\), we denote the image of \(X_i\) +under the inclusion \(\mathfrak{g} \to T \mathfrak{g}\) simply by \(X_i\) and +we write \(X_1 \cdots X_n\) for \((X_1 \otimes \cdots \otimes X_n) + I\). This +notation suggests the map \(\mathfrak{g} \to \mathcal{U}(\mathfrak{g})\) is +injective, but at this point this is not at all clear -- since the projection +\(T \mathfrak{g} \to \mathcal{U}(\mathfrak{g})\) is not injective. However, we +will soon see this is the case. Intuitively, \(\mathcal{U}(\mathfrak{g})\) is +the smallest associative \(K\)-algebra containing \(\mathfrak{g}\) as a Lie +subalgebra. In practice this means\dots \begin{proposition}\label{thm:universal-env-uni-prop} Let \(\mathfrak{g}\) be a Lie algebra and \(A\) be an associative