- Commit
- d9336d2c01b84402ffb17ec3a0987da1c5f73137
- Parent
- f02b089f3c69404e92749e6d114df5111908ce77
- Author
- Pablo <pablo-escobar@riseup.net>
- Date
Changed the notation for the set of parameters for coherent families
Also changed the script-style font
Source code for my notes on representations of semisimple Lie algebras and Olivier Mathieu's classification of simple weight modules
Changed the notation for the set of parameters for coherent families
Also changed the script-style font
2 files changed, 30 insertions, 32 deletions
Status | File Name | N° Changes | Insertions | Deletions |
Modified | preamble.tex | 2 | 1 | 1 |
Modified | sections/coherent-families.tex | 60 | 29 | 31 |
diff --git a/preamble.tex b/preamble.tex @@ -24,7 +24,7 @@ \usepackage[T1]{fontenc} \usepackage[sc]{mathpazo} \renewcommand*\ttdefault{txtt} -\usepackage[scr=esstix,cal=boondox]{mathalfa} +\usepackage[scr=euler,cal=boondox]{mathalfa} \hypersetup{ colorlinks, citecolor=black,
diff --git a/sections/coherent-families.tex b/sections/coherent-families.tex @@ -147,11 +147,11 @@ Example~\ref{ex:sp-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + \end{proposition} \begin{definition} - We denote by \(\mathscr{Q}\) the set of the \(m \in (\sfrac{1}{2} + + We denote by \(\mathscr{B}\) the set of the \(m \in (\sfrac{1}{2} + \mathbb{Z})^n\) such that \(m_1 > m_2 > \cdots > m_{n - 1} > \pm m_n\). We - also consider the canonical partition \(\mathscr{Q} = \mathscr{Q}^+ \cup - \mathscr{Q}^-\) where \(\mathscr{Q}^+ = \{ m \in \mathscr{Q} : m_n > 0 \}\) - and \(\mathscr{Q}^- = \{ m \in \mathscr{Q} : m_n < 0\}\). + also consider the canonical partition \(\mathscr{B} = \mathscr{B}^+ \cup + \mathscr{B}^-\) where \(\mathscr{B}^+ = \{ m \in \mathscr{B} : m_n > 0 \}\) + and \(\mathscr{B}^- = \{ m \in \mathscr{B} : m_n < 0\}\). \end{definition} % TODO: Prove this @@ -164,7 +164,7 @@ Example~\ref{ex:sp-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + \mExt(L(\mu))\) if, and only if \(m(\lambda)_i = m(\mu)_i\) for \(i < n\) and \(m(\lambda)_n = \pm m(\mu)_n\). In particular, the isomorphism classes of semisimple irreducible coherent \(\mathfrak{sp}_{2n}(K)\)-families are - parameterized by \(\mathscr{Q}^+\). + parameterized by \(\mathscr{B}^+\). \end{theorem} \section{Coherent \(\mathfrak{sl}_n(K)\)-families} @@ -234,16 +234,14 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + + 1}\) is \emph{not} a positive integer. \end{proposition} -% TODO: Change the notation for 𝓟 ? The paper on affine vertex algebras calls -% this graph 𝓑 -% TODO: Explain the significance of 𝓟 + and 𝓟 -: these are the subsets whose +% TODO: Explain the significance of 𝓑 + and 𝓑 -: these are the subsets whose % union corresponds to condition (i) \begin{definition} - We denote by \(\mathscr{P}\) the set of \(\mathfrak{sl}_n\)-sequences \(m\) + We denote by \(\mathscr{B}\) the set of \(\mathfrak{sl}_n\)-sequences \(m\) such that \(m_i - m_{i + 1}\) is a positive integer for all but a single \(i - < n\). We also consider the subsets \(\mathscr{P}^+ = \{m \in \mathscr{P} : - m_1 - m_2 \ \text{is \emph{not} a positive integer}\}\) and \(\mathscr{P}^- = - \{m \in \mathscr{P} : m_{n-1} - m_n \ \text{is \emph{not} a positive + < n\). We also consider the subsets \(\mathscr{B}^+ = \{m \in \mathscr{B} : + m_1 - m_2 \ \text{is \emph{not} a positive integer}\}\) and \(\mathscr{B}^- = + \{m \in \mathscr{B} : m_{n-1} - m_n \ \text{is \emph{not} a positive integer}\}\). \end{definition} @@ -252,7 +250,7 @@ Example~\ref{ex:sl-canonical-basis}. Also fix \(\rho = \sfrac{1}{2} \beta_1 + % implies L(μ) is contained in 𝓔𝔁𝓽(L(λ)) - so that L(μ) is also bounded and % 𝓔𝔁𝓽(L(λ)) ≅ 𝓔𝔁𝓽(L(μ)) \begin{definition} - Given \(m, m' \in \mathscr{P}\), say there is an arrow \(m \to m'\) if + Given \(m, m' \in \mathscr{B}\), say there is an arrow \(m \to m'\) if the unique \(i\) such that \(m_i - m_{i + 1}\) is not a positive integer is such that \(m' = \sigma_i \cdot m\). \end{definition} @@ -261,8 +259,8 @@ It should then be obvious that\dots \begin{proposition} Let \(\lambda \notin P^+\) be such that \(L(\lambda)\) is bounded -- so that - \(m(\lambda) \in \mathscr{P}\) -- and suppose that \(\mu \in \mathfrak{h}^*\) - is such that \(m(\mu) \in \mathscr{P}\) and there is an arrow \(m(\lambda) + \(m(\lambda) \in \mathscr{B}\) -- and suppose that \(\mu \in \mathfrak{h}^*\) + is such that \(m(\mu) \in \mathscr{B}\) and there is an arrow \(m(\lambda) \to m(\mu)\). Then \(L(\mu)\) is also bounded and \(\mExt(L(\mu)) \cong \mExt(L(\lambda))\). \end{proposition} @@ -278,7 +276,7 @@ all \(i \ne j\) or \(m_i = m_j\) for some \(i \ne j\), respectively. Similarly, \(\mathfrak{sl}_n\)-sequence \(m\) integral if \(m_i - m_j \in \mathbb{Z}\) for all \(i\) and \(j\). -% TODO: Add notes on what are the sets W ⋅m ∩ 𝓟 : the connected component of +% TODO: Add notes on what are the sets W ⋅m ∩ 𝓑 : the connected component of % a given element is contained in its orbit, but a given orbit may contain % multiple connected components. When m is regular and integral then its orbit % is the union of n connected components, but otherwise its orbit is precisely @@ -287,11 +285,11 @@ all \(i\) and \(j\). % theorem? Perhaps it's best to create another lemma for this % TODO: Restate the notation for σ_i beforehand \begin{proposition} - The connected component of some \(m \in \mathscr{P}\) is given by the + The connected component of some \(m \in \mathscr{B}\) is given by the following. \begin{enumerate} \item If \(m\) is regular and integral then there exists\footnote{Notice - that in this case $m' \notin \mathscr{P}$, however.} a unique \(m' \in W + that in this case $m' \notin \mathscr{B}$, however.} a unique \(m' \in W \cdot m\) such that \(m_1' > m_2' > \cdots > m_n'\), in which case the connected component of \(m\) is given by \[ @@ -312,8 +310,8 @@ all \(i\) and \(j\). \end{tikzcd} \] for some unique \(i\), with \(\sigma_1 \cdots \sigma_i \cdot m' \in - \mathscr{P}^+\) and \(\sigma_{n-1} \cdots \sigma_i \cdot m' \in - \mathscr{P}^-\). + \mathscr{B}^+\) and \(\sigma_{n-1} \cdots \sigma_i \cdot m' \in + \mathscr{B}^-\). \item If \(m\) is singular then there exists unique \(m' \in W \cdot m\) and \(i\) such that \(m_1' > m_2' > \cdots > m_i' = m_{i + 1}' > \cdots > @@ -335,8 +333,8 @@ all \(i\) and \(j\). \sigma_{n-1} \cdots \sigma_{i+1} \cdot m' \lar & \end{tikzcd} \] - with \(\sigma_1 \cdots \sigma_{i-1} \cdot m' \in \mathscr{P}^+\) and - \(\sigma_{n-1} \cdots \sigma_{i+1} \cdot m' \in \mathscr{P}^-\). + with \(\sigma_1 \cdots \sigma_{i-1} \cdot m' \in \mathscr{B}^+\) and + \(\sigma_{n-1} \cdots \sigma_{i+1} \cdot m' \in \mathscr{B}^-\). \item If \(m\) is non-integral then there exists unique \(m' \in W \cdot m\) such that \(m_2' > m_3' > \cdots > m_n'\), in which case the @@ -350,16 +348,16 @@ all \(i\) and \(j\). \sigma_{n-1} \cdots \sigma_1 \cdot m' \lar & \end{tikzcd} \] - with \(m' \in \mathscr{P}^+\) and \(\sigma_{n-1} \cdots \sigma_1 \cdot m' - \in \mathscr{P}^-\). + with \(m' \in \mathscr{B}^+\) and \(\sigma_{n-1} \cdots \sigma_1 \cdot m' + \in \mathscr{B}^-\). \end{enumerate} \end{proposition} -% TODO: Add pictures of parts of the graph 𝓟 ? +% TODO: Add pictures of parts of the graph 𝓑 ? -% TODO: Notice that this gives us that if m(λ)∈ 𝓟 then L(λ) is bounded: for λ -% ∈ 𝓟 + ∪ 𝓟 - we stablish this by hand, and for the general case it suffices to -% notice that there is always some path μ → ... → λ with μ ∈ 𝓟 + ∪ 𝓟 - +% 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 @@ -367,11 +365,11 @@ all \(i\) and \(j\). \begin{theorem}[Mathieu] Given \(\lambda, \mu \notin P^+\) with \(L(\lambda)\) and \(L(\mu)\) bounded, \(\mExt(L(\lambda)) \cong \mExt(L(\mu))\) if, and only if \(m(\lambda)\) and - \(m(\mu)\) lie in the same connected component of \(\mathscr{P}\). In + \(m(\mu)\) lie in the same connected component of \(\mathscr{B}\). In particular, the isomorphism classes of semisimple irreducible coherent \(\mathfrak{sl}_n(K)\)-families are parameterized by the set - \(\pi_0(\mathscr{P})\) of the connected components of \(\mathscr{P}\), as - well as by \(\mathscr{P}^+\). + \(\pi_0(\mathscr{B})\) of the connected components of \(\mathscr{B}\), as + well as by \(\mathscr{B}^+\). \end{theorem} % TODO: Change this