This commit is contained in:
@@ -88,28 +88,6 @@
|
||||
and $\lambda(x_0, y - y_0) \in U$ as well. Therefore $\alg$ is equicontinuous at $(x_0, y_0)$.
|
||||
\end{proof}
|
||||
|
||||
|
||||
|
||||
\begin{theorem}
|
||||
\label{theorem:separate-joint-bilinear}
|
||||
Let $E, F, G$ be TVSs over $K \in \RC$ and $\alg$ be separately continuous bilinear maps from $E \times F$ to $G$. If one of the following holds:
|
||||
\begin{enumerate}
|
||||
\item[(B)] $E$ is Baire.
|
||||
\item[(B')] $E$ is barrelled and $G$ is locally convex.
|
||||
\end{enumerate}
|
||||
|
||||
and that
|
||||
\begin{enumerate}
|
||||
\item[(M)] $E$ and $F$ are both metrisable.
|
||||
\item[(E)] For each $x \in E$, $\bracsn{\lambda(x, \cdot)|\lambda \in \alg} \subset L(F; G)$ is equicontinuous.
|
||||
\end{enumerate}
|
||||
|
||||
then $\alg$ is equicontinuous.
|
||||
\end{theorem}
|
||||
\begin{proof}[Proof, {{\cite[III.5.1]{SchaeferWolff}}}. ]
|
||||
Let $\seq{(x_n, y_n)} \subset E \times F$ and $\seq{\lambda_n} \subset \alg$ such that $(x_n, y_n) \to 0$ as $n \to \infty$. Since $\seq{y_n}$ is convergent, for each $n \in \natp$ and $x \in E$, $\bracsn{\lambda_n(x, y_n)|n \in \natp}$ is bounded by (E) and \autoref{proposition:equicontinuous-net}. By (B) or (B') and the \hyperref[Banach-Steinhaus Theorem]{theorem:banach-steinhaus}, $\bracsn{\lambda_n(\cdot, y_n)|n \in \natp}$ is equicontinuous, and $\lambda_n(x_n, y_n) \to 0$ as $n \to \infty$ by \autoref{proposition:equicontinuous-net}. By (M) and \autoref{proposition:equicontinuous-net}, $\alg$ is equicontinuous at $0$, and hence equicontinuous by \autoref{lemma:equicontinuous-bilinear}.
|
||||
\end{proof}
|
||||
|
||||
% TODO: Replace this with a more general version involving polars in the future.
|
||||
\begin{theorem}[Banach-Alaoglu]
|
||||
\label{theorem:alaoglu}
|
||||
|
||||
Reference in New Issue
Block a user