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Viewing Version 1 of 'holomorphically convex'
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Title of object: holomorphically convex
Canonical Name: HolomorphicallyConvex
Type: Definition

Created on: 2005-02-22 12:54:35
Modified on: 2005-02-22 12:54:35

Creator: jirka
Modifier: jirka
Author: jirka

Classification: msc:32E05
Defines: holomorphically convex hull
Synonyms: holomorphically convex=holomorph-convex

Revision comment (for changes between this and next version):

Changes for correction #5970 ('use of domain').

Preamble:

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Let ${\mathcal{O}}(G)$ stand for the set of functions holomorphic on a domain $G$.

\begin{defn}
Let $K \subset G \subset {\mathbb{C}}^n$ be a compact set, where $G$ is an open domain.
We define the {\em holomoprhically \PMlinkescapetext{convex hull}} of $K$ as
\begin{equation*}
\hat{K}_G := \{ z \in G \mid \lvert f(z) \rvert \leq \sup_{w \in K} \lvert f(w) \rvert \text{ for all } f \in {\mathcal{O}}(G) \} .
\end{equation*}
The domain $G$ is called {\em holomorhpically convex} if for every $K \subset G$ compact in $G$, $\hat{K}_G$ is also compact in $G$.
\end{defn}

Note that when $n=1$, any domain $G$ is holomorphically convex. Also note that this is the same as being a domain of holomorphy.

The above definition is also used when $G$ is not a domain of ${\mathbb{C}}^n$
but is in fact a complex analytic manifold. All that is required is then to remove the ${\mathbb{C}}^n$ from the definition.

\begin{thebibliography}{9}
\bibitem{Hormander:several}
Lars H\"ormander.
{\em \PMlinkescapetext{An Introduction to Complex Analysis in Several
Variables}},
North-Holland Publishing Company, New York, New York, 1973.
\bibitem{Krantz:several}
Steven~G.\@ Krantz.
{\em \PMlinkescapetext{Function Theory of Several Complex Variables}},
AMS Chelsea Publishing, Providence, Rhode Island, 1992.
\end{thebibliography}