- Commit
- 88fc21975aa53fb4a9d3bd9dbba6ecd603f05c38
- Parent
- 68397c8ab26e4779ea52188105d238176104fa8b
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Revised some TODO items
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Revised some TODO items
1 file changed, 21 insertions, 18 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | sections/coherent-families.tex | 39 | 21 | 18 |
diff --git a/sections/coherent-families.tex b/sections/coherent-families.tex @@ -1,7 +1,7 @@ \chapter{Classification of Coherent Families} -% TODOO: Is this decomposition unique?? -% TODO: Prove this +% TODOOO: Is this decomposition unique?? +% TODOO: Prove this \begin{proposition} Suppose \(\mathfrak{g} = \mathfrak{s}_1 \oplus \cdots \oplus \mathfrak{s}_r\) and let \(\mathcal{M}\) be a semisimple irreducible coherent @@ -84,7 +84,8 @@ combinatorial counterpart. % TODO: Note we will prove that central characters are also invariants of % coherent families -% TODO: Prove this + +% TODOO: Prove this \begin{proposition}[Mathieu]\label{thm:coherent-family-has-uniq-central-char} Suppose \(\lambda, \mu \in \mathfrak{h}^*\) are such that \(L(\lambda)\) and \(L(\mu)\) are both bounded and \(\mExt(L(\lambda)) \cong \mExt(L(\mu))\). @@ -92,7 +93,8 @@ combinatorial counterpart. \end{proposition} % TODO: Remark that the probability of σ_β ∙ λ ∈ P+ is slight: there precisely -% one eleement in the orbit of λ which is dominant integral +% one element in the orbit of λ which is dominant integral, so the odds are +% 1/|W ∙ λ| \begin{proposition}\label{thm:lemma6.1} Let \(\beta \in \Sigma\) and \(\lambda \notin P^+\) be such that. \(L(\lambda)\) is bounded and \(\lambda(H_\beta) \notin \mathbb{N}\). Then @@ -102,7 +104,7 @@ combinatorial counterpart. \(\mExt(L(\sigma_\beta \bullet \lambda)) \cong \mExt(L(\lambda))\). \end{proposition} -% TODOO: Treat the case of sl(2) here? +% TODOO: Treat the case of sl(2) here \section{Coherent \(\mathfrak{sp}_{2n}(K)\)-families} @@ -119,6 +121,9 @@ the \(i\)-th entry of the diagonal of a given matrix, as described in Example~\ref{ex:sp-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + \cdots + \sfrac{1}{2} \beta_n\). +% TODO: Add some comments on the proof of this: verifying that these conditions +% are necessary is a purely combinatorial affair, while checking that these are +% sufficient involves some analysis envolving the Shane-Weil module \begin{lemma}\label{thm:sp-bounded-weights} Then \(L(\lambda)\) is bounded if, and only if \begin{enumerate} @@ -244,10 +249,8 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + % TODO: Add some comments on the proof of this: while the proof that these % conditions are necessary is a purely combinatorial affair, the proof of the % fact that conditions (ii) and (iii) imply L(λ) is bounded requires some -% results on the connected components of of the graph ℘ (which we will only +% results on the connected components of of the graph 𝓑 (which we will only % state later down the line) -% TODO: Change the notation for A(λ)? I hate giving objets genereic names, but -% there really isn't any reasonable name for it \begin{lemma}\label{thm:sl-bounded-weights} Let \(\lambda \notin P^+\) and \(A(\lambda) = \{ i : \lambda(H_{\beta_i})\ \text{is \emph{not} a non-negative integer}\}\). Then \(L(\lambda)\) is @@ -275,8 +278,6 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + % TODO: Revise the notation for this? I don't really like calling this % bijection m -% TODO: Note that this prove is similar to the previous one, and that the -% equivariance of the map follows from the nature of the isomorphism W ≅ S_n \begin{proposition} The map \begin{align*} @@ -299,9 +300,13 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + \emph{not} ordered, but becomes ordered after removing one term. \end{proposition} -% TODO: Note the normalization constant 2n is choosen because +% TODOO: Note that this prove is similar to the previous one, and that the +% equivariance of the map follows from the nature of the isomorphism W ≅ S_n +% TODO: The normalization constant 2n is choosen because % λ(H_β) = 2n κ(λ, β) and m(λ) is thus uniquely characterized by the fact that -% (λ + ρ)(H_β_i) = m(λ)_i - m(λ)_i+1 +% (λ + ρ)(H_β_i) = m(λ)_i - m(λ)_i+1. This comes in when verifying the +% equivalence between the conditions of the previous lemma and those described +% in the theorem % TODO: Explain the significance of 𝓑 + and 𝓑 -: these are the subsets whose % union corresponds to condition (i) @@ -314,10 +319,12 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + \text{is ordered}\}\). \end{definition} +% TODO: Add a picture of parts of 𝓑 for n = 3 in here + % TODO: Explain that for each m ∈ 𝓑 there is a unique i such that so that % m_i - m_i+1 is not a positive integer. For m ∈ 𝓑 + this is i = 1, while for % m ∈ 𝓑 - this is i = n-1 -% TODO: Explain the intuition behind defining the arrows like so: the point is +% TODOO: Explain the intuition behind defining the arrows like so: the point is % that if there is an arrow m(λ) → m(μ) then μ = σ_i ∙ λ for some i, which % implies L(μ) is contained in 𝓔𝔁𝓽(L(λ)) - so that L(μ) is also bounded and % 𝓔𝔁𝓽(L(λ)) ≅ 𝓔𝔁𝓽(L(μ)) @@ -378,7 +385,7 @@ all \(i\) and \(j\). \mathscr{B}^+\) and \(\sigma_{n-1} \cdots \sigma_i \cdot m' \in \mathscr{B}^-\). - % TODOO: What happens when i = 1?? Do we need to suppose i > 1? + % TODOOO: What happens when i = 1?? Do we need to suppose i > 1? % TODO: For instance, consider m = (1, 1, -2) \item If \(m\) is singular then there exists unique \(m' \in W \cdot m\) and \(i\) such that \(m'_i = m'_{i + 1}\) and \((m_1', \cdots, m_{i-1}', @@ -421,13 +428,9 @@ all \(i\) and \(j\). \end{enumerate} \end{lemma} -% TODO: Add pictures of parts of the graph 𝓑 ? - % TODO: Notice that this gives us that if m(λ)∈ 𝓑 then L(λ) is bounded: for λ % ∈ 𝓑 + ∪ 𝓑 - we stablish this by hand, and for the general case it suffices to % notice that there is always some path μ → ... → λ with μ ∈ 𝓑 + ∪ 𝓑 - -% TODO: Perhaps this could be incorporated into the discussion of the lemma -% that characterizes the weights of sl(n) whose L is bounded \begin{theorem}[Mathieu] Given \(\lambda, \mu \notin P^+\) with \(L(\lambda)\) and \(L(\mu)\) bounded,