Extensions of the notions of polynomial and rational hull are introduced. Using these notions, a generalization of a result of Duval and Levenberg on polynomial hulls containing no analytic discs is presented. As a consequence it is shown that there exists a Cantor set in C 3 with a nontrivial polynomial hull that contains no analytic discs. Using this Cantor set, it is shown that there exist arcs and simple closed curves in C 4 with nontrivial polynomial hulls that contain no analytic discs. This answers a question raised by Bercovici in 2014 and can be regarded as a partial answer to a question raised by Wermer over 60 years ago. More generally, it is shown that every uncountable, compact subspace of a Euclidean space can be embedded as a subspace X of C N , for some N , in such a way as to have a nontrivial polynomial hull that contains no analytic discs. In the case when the topological dimension of the space is at most one, X can be chosen so as to have the stronger property that P (X) has a dense set of invertible elements.
Abstract. It is shown that there exists a compact set X in C N (N ≥ 2) such that X \ X is nonempty and the uniform algebra P (X) has a dense set of invertible elements, a large Gleason part, and an abundance of nonzero bounded point derivations. The existence of a Swiss cheese X such that R(X) has a Gleason part of full planar measure and a nonzero bounded point derivation at almost every point is established. An analogous result in C N is presented. The analogue for rational hulls of a result of Duval and Levenberg on polynomial hulls containing no analytic discs is established. The results presented address questions raised by Dales and Feinstein.
Dedicated to Andrew Browder
We study extensions of Wermer's maximality theorem to several complex
variables. We exhibit various smoothly embedded manifolds in complex Euclidean
space whose hulls are non-trivial but contain no analytic disks. We answer a
question posed by Lee Stout concerning the existence of analytic structure for
a uniform algebra whose maximal ideal space is a manifold.Comment: Comments are welcome
We establish the peak point conjecture for uniform algebras generated by smooth functions on twomanifolds: if A is a uniform algebra generated by smooth functions on a compact smooth two-manifold M, such that the maximal ideal space of A is M, and every point of M is a peak point for A, then A = C(M). We also give an alternative proof in the case when the algebra A is the uniform closure P (M) of the polynomials on a polynomially convex smooth two-manifold M lying in a strictly pseudoconvex hypersurface in C n .
In this paper it is shown that every compact two-dimensional manifold S, with or without boundary, can be embedded in C 3 as a smooth submanifold Σ in such a way that the polynomially convex hull of Σ, though strictly larger than Σ, contains no analytic disc.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.