English

Analytic Disks and the Projective Hull

Complex Variables 2008-08-21 v2 Differential Geometry

Abstract

Let X be a complex manifold and c a simple closed curve in X. We address the question: What conditions on c ensure the existence of a 1-dimensional complex subvariety V with boundary c in X. When X = C^n, an answer to this question involves the polynomial hull of gamma. When X = P^n, complex projective space, the projective hull hat{c} of c comes into play. One always has V contained in hat{c}, and for analytic curves they conjecturally coincide. In this paper we establish an approximate analogue of this idea which holds without the analyticity of c. We characterize points in hat{c} as those which lie on a sequence of analytic disks whose boundaries converge down to c. This is in the spirit of work of Poletsky and of Larusson-Sigurdsson, whose work is essential here. The results are applied to construct a remarkable example of a closed curve c in P^2, which is real analytic at all but one point, and for which the closure of hat{c} is W \cup L where L is a projective line and W is an analytic (non-algebraic) subvariety of P^2 - L. Furthermore, hat{c} itself is the union of W with only two points on L.

Keywords

Cite

@article{arxiv.0806.4776,
  title  = {Analytic Disks and the Projective Hull},
  author = {H. Blaine Lawson and John Wermer},
  journal= {arXiv preprint arXiv:0806.4776},
  year   = {2008}
}

Comments

Minor misprints have been corrected

R2 v1 2026-06-21T10:55:37.359Z