- Commit
- c30d5168dc0bc9905e09e23150177084fa2121fe
- Parent
- 9023cb603450f4960c343c5e26651add2ca502d1
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Fixed an error
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Fixed an error
1 file changed, 4 insertions, 19 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | sections/mathieu.tex | 23 | 4 | 19 |
diff --git a/sections/mathieu.tex b/sections/mathieu.tex @@ -1141,34 +1141,19 @@ if twist \(\Sigma^{-1} V\) by an automorphism which shifts its support by some \(\lambda \in \mathfrak{h}^*\), we can construct a coherent family by summing this modules over \(\lambda\) as in example~\ref{ex:sl-laurent-family}. -% TODOOOOOOO: Are you sure these maps factor trought automorphisms of the -% localization? -% TODO: It doesn't! In fact, the homomorphism U(sl2) -> K[x, 1/x, d/dx] CANNOT -% be extended to U(sl2)_f, given that the image of f is not invertible in -% K[x, 1/x, d/dx] (no operators of positive order is invertible in -% K[x, 1/x, d/dx]) -% TODO: Fix this! For \(K[x, x^{-1}]\) this was achieved by twisting the \(\operatorname{Diff}(K[x, x^{-1}])\)-module \(K[x, x^{-1}]\) by the automorphisms \(\varphi_\lambda : \operatorname{Diff}(K[x, x^{-1}]) \to \operatorname{Diff}(K[x, x^{-1}])\) and restricting the results to \(\mathcal{U}(\mathfrak{sl}_2(K))\) via the map \(\mathcal{U}(\mathfrak{sl}_2(K)) \to \operatorname{Diff}(K[x, x^{-1}])\), but -we could just as well twist \(K[x, x^{-1}]\) by automorphisms of +this approch is inflexible since not every representation of +\(\mathfrak{sl}_2(K)\) factors through \(\operatorname{Diff}(K[x, x^{-1}])\). +Nevertheless, we could just as well twist \(K[x, x^{-1}]\) by automorphisms of \(\mathcal{U}(\mathfrak{sl}_2(K))_f\) directly -- where \(\mathcal{U}(\mathfrak{sl}_2(K))_f\) denotes the localization of \(\mathcal{U}(\mathfrak{sl}_2(K))\) by the multiplicative subset generated by -\(f\). In fact, \(\varphi_\lambda\) factors trought an automorphism -\(\theta_\lambda :\mathcal{U}(\mathfrak{sl}_2(K))_f \to -\mathcal{U}(\mathfrak{sl}_2(K))_f\). -\begin{center} - \begin{tikzcd} - \mathcal{U}(\mathfrak{sl}_2(K))_f \rar \dar[dotted, swap]{\theta_\lambda} & - \operatorname{Diff}(K[x, x^{-1}]) \dar{\varphi_\lambda} \\ - \mathcal{U}(\mathfrak{sl}_2(K))_f \rar & - \operatorname{Diff}(K[x, x^{-1}]) - \end{tikzcd} -\end{center} +\(f\). In general, we may twist the \(\Sigma^{-1} \mathcal{U}(\mathfrak{g})\)-module \(\Sigma^{-1} V\) by automorphisms of \(\Sigma^{-1}