- Commit
- 41970a21d4049b597fabe37789921cc30cbfe48b
- Parent
- 26deb194e1f37cb5e74b4fa66045e52ebf48d511
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Fixed a typo
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Fixed a typo
1 file changed, 3 insertions, 3 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | sections/complete-reducibility.tex | 6 | 3 | 3 |
diff --git a/sections/complete-reducibility.tex b/sections/complete-reducibility.tex @@ -614,8 +614,8 @@ obstructions to complete reducibility. Explicitly\dots \begin{theorem} Given \(\mathfrak{g}\)-modules \(N\) and \(L\), there is a one-to-one - correspondence between elements of \(H^1(\mathfrak{g}, \operatorname{Hom}(N, - L))\) and isomorphism classes of short exact sequences + correspondence between elements of \(H^1(\mathfrak{g}, \operatorname{Hom}(L, + N))\) and isomorphism classes of short exact sequences \begin{center} \begin{tikzcd} 0 \rar & N \rar & M \rar & L \rar & 0 @@ -647,7 +647,7 @@ for further details. We will use the previous result implicitly in our proof, but we will not prove it in its full force. Namely, we will show that if \(\mathfrak{g}\) is semisimple then \(H^1(\mathfrak{g}, M) = 0\) for all finite-dimensional \(M\), -and that the fact that \(H^1(\mathfrak{g}, \operatorname{Hom}(N, L)) = 0\) for +and that the fact that \(H^1(\mathfrak{g}, \operatorname{Hom}(L, N)) = 0\) for all finite-dimensional \(N\) and \(L\) implies complete reducibility. To that end, we introduce a distinguished element of \(\mathcal{U}(\mathfrak{g})\), known as \emph{the Casimir element of a \(\mathfrak{g}\)-module}.