Abstract
Let Ω be a bounded strictly pseudoconvex domain in ℂn, n ≥ 3, with boundary ∂Ω, of class C2. A compact subset K is called removable if any analytic function in a suitable small neighborhood of ∂Ω K extends to an analytic function in Ω. We obtain sufficient conditions for removability in geometric terms under the condition that K is contained in a generic C2 -submanifold M of co-dimension one in ∂Ω. The result uses information on the global geometry of the decomposition of a CR-manifold into CR-orbits, which may be of some independent interest. The minimal obstructions for removability contained in M are compact sets K of two kinds. Either K is the boundary of a complex variety of co-dimension one in Ω or it is an exceptional minimal CR-invariant subset of M, which is a certain analog of exceptional minimal sets in co-dimension one foliations. It is shown by an example that the latter possibility may occur as a nonremovable singularity set.
Further examples show that the germ of envelopes of holomorphy of neighborhoods of ∞Ω K for K ⊂ M may be multisheeted. A couple of open problems are discussed.
Similar content being viewed by others
References
Airapetian, R.A. Continuation of CR-functions from piecewise smooth CR-manifolds,Mat. Sb.,134(176), 108–118, (1987).
Anderson, J.T. and Cima, J.A. Removable singularities for Lp CR-functions,Mich. Math. J.,41, 111–119, (1994).
Baouendi, M.S. and Treves, F. A property of the functions and distributions annihilated by a locally integrable system of complex vector fields,Ann. Math.,113, 387–421, (1981).
Berndtsson, B. and Ransford, T.J. Analytic multifunctions, the\(\bar \partial \)-equation, and a proof of the corona theorem,Pacif. J. Math.,124, 57–72, (1986).
Čirka, E.M.Complex Analytic Sets (Russian). Moscow, Nauka 1985; English translation, Kluwer, Dordrecht, 1989.
Čirka, E.M. and Stout, E.L. Removable singularities in the boundary, Contributions to Complex Analysis and Analytic Geometry, dedicated to P. Dolbeault, Vieweg, Ed., H. Skoda, J.-M. Trépreau, 43–104.
Dimca, A. Personal communication.
Duval, J. Surfaces convexes dans un bord pseudoconvex,Astérisque,217(6), 103–118, (1993).
Duval, J. and Sibony, N. Polynomial convexity, rational convexity and currents,Duke Math. J.,79, 487–519 (1995).
Fornæss, J.E. and Sibnony, N. Plurisubharmonic functions on ring domains,Lecture Notes in Math.,1268, 111–120, Springer, Berlin, 1987.
Forstnerič, F. On the boundary regularity of proper mappings,Annali Scuola Normale Sup. Pisa, Ser., IV, XIII, 109–128 (1986).
Forstnerič, F. and Stout, E.L. A new class of polynomially convex sets,Ark. för Mat.,29, 51–62 (1991).
Ghys, E. Personal communication.
Golubitski, M. and Guillermin, V.Stable Mappings and Their Singularities, Springer, New York, 1973.
Grauert, H. On Levi’s problem,Ann. Math.,68(2), 460–472, (1958).
Greenfield, S.J. Cauchy-Riemann equations in several variables,Ann. Scuola Norm. Sup. Pisa,22, 275–314, (1968).
Hartmann, Ph.Ordinary Differential Equations, John Wiley & Sons, New York, 1964.
Harvey, F.R. and Lawson, H.B. On boundaries of complex analytic varieties, I,Ann. Math.,102, 223–290, (1975).
Hector, G. and Hirsch, U.Introduction to the Geometry of Foliations, Part A & Part B, Fr. Vieweg & Sohn, Braunschweig/Wiesbaden, 1983.
Hörmander, L.An Introduction to Complex Analysis in Several Variables, D. van Nostrand, Princeton, NJ, 1966.
Jöricke, B. Removable singularities of CR-functions,Ark. för Mat.,26, 117–143, (1988).
Jöricke, B. Envelopes of holomorphy and CR-invariant subsets of CR-manifolds,C.R. Acad. Sc. Paris,315, Sér. I, 407–411, (1992).
Jöricke, B. Some remarks concerning holomorphically convex hulls and envelopes of holomorphy,Math. Z.,218, 143–157, (1995).
Jöricke, B. Deformation of CR-manifolds, minimal points and CR-manifolds with the microlocal analytic extension property.J. Geom. Anal., v.6, n. 4, 555–611, (1996).
Lawrence, M. Hulls of tame Cantor sets. To appear.
Lehner, J. Discontinuous groups and automorphic functions,Math. Surv.,8, AMS, Providence, RI, (1964).
Lupacciolu, G. Characterization of removable sets in strongly pseudoconvex boundaries,Ark. för Math.,32, 455–473, (1994).
Lupacciolu, G. and Stout, E.M. Removable Singularities for\(\bar \partial _b \), Proc. Mittag-Leffler special year in complex analysis, Princeton University Press, Princeton, NJ, 1993.
Marshall, D. Removable sets for bounded analytic functions,Lecture Notes in Math.,1043, 485–490, Springer, Berlin, (1984).
Narasimhan, R. Introduction to the theory of analytic spaces,Lect. Notes in Math.,25, Springer, Berlin, (1966).
Painlevé, P. Sur les lignes singulières des fondons analytiques,Ann. Fac. Sci. Toulouse,2, (1888).
Slodkowski, Z. An analytic set valued selection and its application to the corona theorem, to polynomial hulls and joint spectra,Trans. Am. Math. Soc.,294(1), 367–377, (1986).
Springer, G.Introduction to Riemann Surfaces, Addison-Wesley, Massachusetts, 1957.
Stolzenberg, G. Polynomially and rationally convex sets,Acta Math.,109, 259–289, (1963).
Stolzenberg, G. Uniform approximation on smooth curves,Acta Math.,115, 185–198, (1966).
Stout, E.L.Removable Singularities for the Boundary Values of Holomorphic Functions of Several Complex Variables, Proc. Mittag-Leffier special year in complex variables, Princeton University Press, Princeton, NJ, 1993.
Stout, E.L. Harmonic duality, hyperfunctions and removable singularities,Izvestiya Rus. Acad. Sci., Ser. Math.,59(6), 133–170, (1995).
Sussmann, H.J. Orbits of families of vector fields and integrability of distributions,Trans. Am. Math. Soc.,180, 171–188, (1973).
Trépreau, J.-M. Sur la propagation des singularités dans les variétiés CR,Bull. Soc. Math. France,118, 403–450, (1990).
Trépreau, J.-M.Holomorphic Extension of CR-Functions: A Survey, Progress in non-linear differential equations and their applications, The Danish-Swedish Analysis Seminar 1995. Birkhäuser, Boston, 1996.
Treves, F.Approximation and Representation of Functions and Distributions Annihilated by a System of Complex Vector Fields, École Polytech., Centre de Math., Palaiseau, France, 1981.
Tumanov, A.E. Extension of CR-functions into a wedge from a manifold of finite type,Mat. Sbornik,136, 129–140, (1988).
Tumanov, A.E. Extension of CR-functions into a wedge,Mat. Sbornik,181, 951–964, (1990).
Tumanov, A.E. Connections and propagation of analyticity for CR-functions,Duke Math. J.,73, 1–24, (1994).
Vladimirov, V.S.Fonctions de Plusieurs Variables Complexes, Dunod, Paris, 1971.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jöricke, B. Boundaries of singularity sets, removable singularities, and CR-invariant subsets of CR-manifolds. J Geom Anal 9, 257–300 (1999). https://doi.org/10.1007/BF02921939
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02921939