Mid Sweden University

We prove that the open unit disc Delta in C satisfies the ball embedding property in C(2); i.e., given any discrete set of discs in C(2) there exists a proper holomorphic embedding Delta hooked right arrow C(2) which passes arbitrarily close to the discs. It is already known that C does not satisfy the ball embedding property in C(2) and that Delta satisfies the ball embedding property in C(n) for n > 2.

We investigate whether a Stein manifold M which allows proper holomorphic embedding into ℂ ⁿ can be embedded in such a way that the image contains a given discrete set of points and in addition follow arbitrarily close to prescribed tangent directions in a neighbourhood of the discrete set. The infinitesimal version was proven by Forstnerič to be always possible. We give a general positive answer if the dimension of M is smaller than n/2 and construct counterexamples for all other dimensional relations. The obstruction we use in these examples is a certain hyperbolicity condition.

We study the number of equivalence classes of proper holomorphic embeddings of a Stein space X into C-n. In this paper we prove that if the automorphism. group of X is a Lie group and there exists a proper holomorphic embedding of X into C-n, 0 < dim X < n, then for any k >= 0 there exist uncountably many non-equivalent proper holomorphic embeddings Φ: X x C-k hooked right arrow C-n x C-k. For k = 0 all embeddings will be proved to satisfy the additional property of C-n\Φ)(X) being (n-dim X)-Eisenman hyperbolic. As a corollary we conclude that there are uncountably many non-equivalent proper holomorphic embeddings of C-k into C-n whenever 0 < k < n.