Séries de Laurent des fonctions holomorphes dans la complexification d'un espace symétrique compact
We consider an action of a connected compact Lie group on a Stein manifold by holomorphic transformations. We prove that the manifold is spherical if and only if there exists an antiholomorphic involution preserving each orbit. Moreover, for a spherical Stein manifold, we construct an antiholomorphic involution, which is equivariant with respect to the Weyl involution of the acting group, and show that this involution stabilizes each orbit. The construction uses some properties of spherical subgroups...
Let Y be an open subset of a reduced compact complex space X such that X - Y is the support of an effective divisor D. If X is a surface and D is an effective Weil divisor, we give sufficient conditions so that Y is Stein. If X is of pure dimension d ≥ 1 and X - Y is the support of an effective Cartier divisor D, we show that Y is Stein if Y contains no compact curves, for all i > 0, and for every point x₀ ∈ X-Y there is an n ∈ ℕ such that is empty or has dimension 0, where is the map from...
Let denote a holomorphic bundle with fiber and with basis . Both and are assumed to be Stein. For a Reinhardt bounded domain of dimension or , we give a necessary and sufficient condition on for the existence of a non-Stein such (Theorem ); for , we give necessary and sufficient criteria for to be Stein (Theorem ). For a Reinhardt bounded domain of any dimension not intersecting any coordinate hyperplane, we give a sufficient criterion for to be Stein (Theorem ).
We study topology of leaves of -dimensional singular holomorphic foliations of Stein manifolds. We prove that for a generic foliation all leaves, except for at most countably many, are contractible, the rest are topological cylinders. We show that a generic foliation is complex Kupka-Smale.
On étudie les espaces de Stein quasi-compacts (i.e. vérifiant pour tout et tout faisceau cohérent sur ). On établit un critère simple pour qu’un espace soit de Stein et on en déduit quelques conséquences.
Soit un espace symétrique hermitien irréducible de type non-compact et soit le semi-groupe associé formé des compressions de . Soit un sous-groupe discret. Nous donnons une condition suffisante pour que le quotient soit une variété de Stein. En outre nous démontrons qu’en général n’est pas de Stein ce qui réfute une conjecture de Achab, Betten et Krötz.