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Related papers: On the Levi problem with singularities

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We show that if $X$ is a Stein space and, if $\Omega \subset X$ is exhaustable by a sequence $\Omega_1 \subset \Omega_2 \subset \ldots \subset \Omega_n \subset \ldots$ of open Stein subsets of $X$, then $\Omega$ is Stein. This generalizes a…

Complex Variables · Mathematics 2025-10-17 Youssef Alaoui

In this article, we prove that if $X$ is a Stein space and $\Omega\subset X$ an increasing sequence of $q$-complete open subsets, then $\Omega$ is $q$-complete.

Complex Variables · Mathematics 2008-03-06 Youssef Alaoui

In this short note, we collect some results regarding the Remmert reduction of holomorphically convex space and its application to a variation of the usual union problem. Classically, the union problem asks the following question: is a…

Complex Variables · Mathematics 2019-03-20 Samuele Mongodi

We discuss the well-known open problems: the local Steiness problem and the union problem.

Complex Variables · Mathematics 2009-05-15 Mihnea Coltoiu

In this article, we prove that if $\Pi: X\rightarrow \Omega$ is an unbranched Riemann domain with $\Omega$ Stein of dimension $n$ and $\Pi$ a locally $q$-complete morphism, then $X$ is cohomologically $q$-complete if $n\geq 3$ and $1\leq…

Complex Variables · Mathematics 2026-01-15 Youssef Alaoui

It is proved that an unbranched Riemann domain $\Pi : X\rightarrow Y$ over an arbitrary Stein complex space of dimension $n\geq 2$ is Stein if and only if $X$ is cohomologically $2$-complete with respect to the structure sheaf…

Complex Variables · Mathematics 2025-12-29 Youssef Alaoui

The density property for a Stein manifold X implies that the group of holomorphic diffeomorphisms of X is infinite-dimensional and, in a certain well-defined sense, as large as possible. We prove that if G is a complex semisimple Lie group…

Complex Variables · Mathematics 2007-05-23 Arpad Toth , Dror Varolin

This paper examines the broad structure on Stein manifolds and how it generalizes the notion of a domain of holomorphy in $\mathbb C^n$. Along with this generalization, we see that Stein manifolds share key properties from domains of…

Complex Variables · Mathematics 2014-12-01 Dustin Tran

Let D be a bounded strongly pseudoconvex domain in a Stein manifold S and let Y be a complex manifold. We prove that the graph of any continuous map from the closure of D to Y which is holomorphic in D admits a basis of open Stein…

Complex Variables · Mathematics 2008-10-15 Franc Forstneric

We discuss domains of holomorphy and several notions of pseudoconvexity (drawing parallels with the corresponding notions from geometric convexity), and present a mostly self-contained solution to the Levi problem. We restrict our attention…

Complex Variables · Mathematics 2014-11-04 Harry J. Slatyer

We show that the group of holomorphic automorphisms of a Stein manifold X of dimension greater than 1 is infinite-dimensional, provided X is a homogeneous space of a holomorphic action of a complex Lie group.

Complex Variables · Mathematics 2008-06-05 Alan Huckleberry , Alexander Isaev

Let X be a Stein manifold, A a closed complex subvariety of X, and f a continuous map from X to a complex manifold Y whose restriction to A is holomorphic. After a homotopic deformation of the Stein structure outside a neighborhood of A in…

Complex Variables · Mathematics 2007-08-16 Franc Forstneric , Marko Slapar

In this paper (a sequel to B. Drinovec Drnovsek and F. Forstneric, Holomorphic curves in complex spaces, Duke Math. J. 139 (2007), 203-253) we obtain existence and approximation results for closed complex subvarieties that are normalized by…

Complex Variables · Mathematics 2011-09-02 Barbara Drinovec Drnovsek , Franc Forstneric

A complex space $X$ is in class ${\mathcal Q}_G$ if it is a semistable quotient of the complement to an analytic subset of a Stein manifold by a holomorphic action of a reductive complex Lie group $G$. It is shown that every pseudoconvex…

Complex Variables · Mathematics 2015-03-09 Stefan Nemirovski

Let E denote a bundle with fiber D and with basis B. Both D and B are assumed to be Stein. For D a Reinhardt bounded domain of dimension d=2 or 3, we give a necessary and sufficient condition on D for the existence of a non-Stein such E…

Complex Variables · Mathematics 2007-05-23 Karl Oeljeklaus , Dan Zaffran

Rosay and Rudin constructed examples of discrete subsets of C^n with remarkable properties. We generalize these constructions from C^n to arbitrary Stein manifolds. We prove: Given a Stein manifold X and a affine variety V of the same…

Complex Variables · Mathematics 2007-05-23 Joerg Winkelmann

Let $X$ be an arbitrary complex surface and $D \subset X$ a domain that has a non compact group of holomorphic automorphisms. A characterization of those domains $D$ that admit a smooth real analytic, finite type boundary orbit accumulation…

Complex Variables · Mathematics 2011-10-19 Kaushal Verma

This paper is concerned with the problem of constructing a smooth Levi-flat hypersurface locally or globally attached to a real codimension two submanifold in $\mathbb C^{n+1}$, or more generally in a Stein manifold, with elliptic CR…

Complex Variables · Mathematics 2024-09-16 Hanlong Fang , Xiaojun Huang , Wanke Yin , Zhengyi Zhou

In this article, we prove that if $\Pi: X\to \Omega$ is a surjective holomorphic map, with $\Omega$ a Stein space and $X$ a complex manifold of dimension $n\geq 3,$ and if, for every $x\in \Omega$ there exists an open neighborhood $U$ such…

Complex Variables · Mathematics 2007-05-23 Youssef Alaoui

It is shown that two strictly pseudoconvex Stein domains with real analytic boundaries have biholomorphic universal coverings provided that their boundaries are locally biholomorphically equivalent. This statement can be regarded as a…

Complex Variables · Mathematics 2009-04-13 Stefan Nemirovski , Rasul Shafikov
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