Tomassini, Giuseppe and Venturini, Sergio: 
Transversally Pseudoconvex Foliations
 Bollettino dell'Unione Matematica Italiana Serie 9 3 (2010), fasc. n.2, p. 267-279,  (English)
pdf (329 Kb), djvu (131 Kb).  | MR 2666358  | Zbl 1197.32014 
Sunto
We consider real analytic foliations $X$ with complex leaves of transversal dimension one and we give the notion of transversal pseudoconvexity. This amounts to require that the transverse bundle $N_{F}$ to the leaves carries a metric $\{\lambda_{j}\}$ on the the fibres such that the tangential (1,1)-form $\Omega = \{\lambda_{j} \bar{\partial}\partial\lambda_{j} - 2\bar{\partial}\lambda_{j}\partial\lambda_{j}\}$ is positive. This condition is of a special interest if the foliation $X$ is 1 complete i.e. admits a smooth exhaustion function $\phi$ which is strongly plusubharmonic along the leaves. In this situation we prove that there exist an open neighbourhood $U$ of $X$ in the complexification $\widetilde{X}$ of $X$ and a non negative smooth function $u : U \to \mathbf{R}$ which is plurisubharmonic in $U$, strongly plurisubharmonic on $U \setminus X$ and such that $X$ is the zero set of $u$. This result has many implications: every compact sublevel $\overline X_{c} = \{ x \in X : \phi \le c \}$ is a Stein compact and if $S(X)$ is the algebra of smooth CR functions on $X$, the restriction map $S(X) \to S(X_{c})$ has a dense image (Theorem 4.1); a transversally pseudoconvex, 1-complete, real analytic foliation $X$ with complex leaves of dimension $n$ properly embeds in $\mathbf{C}^{2n+3}$ by a CR map and the sheaf $S = S_{X}$ of germs of smooth CR functions on $X$ is cohomologically trivial.
Referenze Bibliografiche
[1] 
A. ANDREOTTI - 
H. GRAUERT, 
Théorèmes de finitude pour la cohomologie des espaces complexes, 
Bull. Soc. Math. France, 
90 (
1962), 193-259. | 
fulltext EuDML | 
MR 150342 | 
Zbl 0106.05501[2] 
M. FREEMAN, 
Tangential Cauchy-Riemann equations and uniform approximation, 
Pacific J. Math., 
33 (
1970), 101-108. | 
MR 264117 | 
Zbl 0184.31103[4] 
L. HÖRMANDER, 
An introduction to complex analysis in several variables, 
D. Van Nostrand, Princeton (New Yersey, 
1965). | 
MR 203075[5] 
J. J. KOHN, 
Global regulatity for $\bar\partial$ on weakly pseudo convex manifolds, 
Trans. Am. Math. Soc., 
181 (
1962), 193-259. | 
fulltext (doi) | 
MR 344703