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<record version="1" id="6478">
 <title>Lewy hypersurface</title>
 <name>LewyHypersurface</name>
 <created>2004-11-16 11:47:51</created>
 <modified>2004-11-16 11:47:51</modified>
 <type>Example</type>
<parent id="6099">hypersurface</parent>
 <creator id="4157" name="jirka"/>
 <author id="4157" name="jirka"/>
 <classification>
	<category scheme="msc" code="32V99"/>
 </classification>
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 <content>The real hypersurface in $(z_1,\ldots,z_n) \in {\mathbb{C}}^n$ given by
\begin{equation*}
\operatorname{Im} z_n = \sum_{j=1}^{n-1} \lvert z_j \rvert^2
\end{equation*}
is called the {\em Lewy hypersurface}.  Note that this is a real hypersurface of real dimension $2n-1$.  This is an example of a non-trivial real hypersurface in complex space.  For example it is not biholomorphically equivalent to the hyperplane defined by $\operatorname{Im} z_n = 0$, but it is locally (not globally) biholomorphically equivalent to a unit sphere.


\begin{thebibliography}{9}
\bibitem{ber:submanifold}
M.\@ Salah Baouendi,
Peter Ebenfelt,
Linda Preiss Rothschild.
{\em \PMlinkescapetext{Real Submanifolds in Complex Space and Their Mappings}},
Princeton University Press,
Princeton, New Jersey, 1999.
\end{thebibliography}</content>
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