diff --git a/src/fa/norm/linear.tex b/src/fa/norm/linear.tex index 420affc..4e83d2a 100644 --- a/src/fa/norm/linear.tex +++ b/src/fa/norm/linear.tex @@ -1,4 +1,4 @@ -\section{Linear Maps} +\section{Linear Maps Between Normed Spaces} \label{section:normed-linear-maps} \begin{proposition} diff --git a/src/fa/norm/multilinear.tex b/src/fa/norm/multilinear.tex index 4dac430..c634560 100644 --- a/src/fa/norm/multilinear.tex +++ b/src/fa/norm/multilinear.tex @@ -1,4 +1,4 @@ -\section{Multilinear Maps} +\section{Multilinear Maps Between Normed Spaces} \label{section:normed-multilinear} \begin{proposition} diff --git a/src/fa/tvs/complete-metric.tex b/src/fa/tvs/complete-metric.tex index 4f1543e..6d5e0fc 100644 --- a/src/fa/tvs/complete-metric.tex +++ b/src/fa/tvs/complete-metric.tex @@ -133,3 +133,20 @@ Thus by \autoref{proposition:successive-approximation-all}, $B_F(0, t) \subset T(B_E(0, r)) \in \cn_F(0)$ for all $r > r_0$. As $r_0 > 0$ is arbitrary, $T(U) \in \cn_F(0)$ for all $U \in \cn_E(0)$. Therefore $T$ is open by translation-invariance of the topology on $E$. \end{proof} + +\begin{theorem}[Closed Graph Theorem] +\label{theorem:closed-graph} + Let $E, F$ be complete metric TVSs over $K \in \RC$ and $T \in \hom(E; F)$. If its graph $\Gamma(T) \subset E \times F$ is closed, then $T \in L(E; F)$. +\end{theorem} +\begin{proof} + Given that $E$ and $F$ are both complete metric TVSs, $E \times F$ is a complete metric TVS by \autoref{proposition:product-complete}. Since $\Gamma(T) \subset E \times F$ is a closed subspace of $E \times F$, it is also a complete metric TVS over $K$ by \autoref{proposition:complete-closed}. + + Let $\pi_1: E \times F \to E$ and $\pi_2: E \times F \to F$ be the projection maps of $E \times F$. As $\Gamma(T)$ is the graph of a function, $\pi_1|_{\Gamma(T)}: \Gamma(T) \to E$ is a continuous bijection. By the \hyperref[Open Mapping Theorem]{theorem:open-mapping}, it is an isomorphism. Therefore $T$ may be expressed as the following composition of continuous linear maps + \[ + \xymatrix{ + E \ar@{->}[r]^{\pi_1|_{\Gamma(T)}^{-1}} & \Gamma(T) \ar@{->}[r]^{\pi_2|_{\Gamma(T)}} & F + } + \] + +\end{proof} + diff --git a/src/measure/weak-integral/definition.tex b/src/measure/weak-integral/definition.tex index b052982..aeb2a90 100644 --- a/src/measure/weak-integral/definition.tex +++ b/src/measure/weak-integral/definition.tex @@ -41,4 +41,11 @@ As I know so little about weak integrals, I will Dunning-Kruger myself right now It is at this point that I start to understand why the bidual setup is useful: existence. +\begin{proposition} +\label{proposition:dunford-existence} + Let +\end{proposition} + + +