Polynomial approximation, local polynomial convexity, and degenerate CR singularities

dc.creatorBharali, Gautam
dc.date2005-04-14
dc.date2006-07-05
dc.date.accessioned2026-07-07T06:39:48Z
dc.date.available2026-07-07T06:39:48Z
dc.descriptionWe begin with the following question: given a closed disc $\bar{D}$ in the complex plane and a complex-valued function F in $C(\bar{D})$, is the uniform algebra on $\bar{D}$ generated by z and F equal to $C(\bar{D})$ ? When F is in $C^1(\bar{D})$, this question is complicated by the presence of points in the surface S:=graph(F) that have complex tangents. Such points are called CR singularities. Let $p\in S$ be a CR singularity at which the order of contact of the tangent plane with S is greater than 2; i.e. a degenerate CR singularity. We provide sufficient conditions for S to be locally polynomially convex at the degenerate singularity p. This is useful because it is essential to know whether S is locally polynomially convex at a CR singularity in order to answer the initial question. To this end, we also present a general theorem on the uniform algebra generated by z and F, which we use in our investigations. This result may be of independent interest because it is applicable even to non-smooth, complex-valued F.
dc.description17 pages; final version; restated Thm.1.2 using slightly clearer notation, corrected minor typos
dc.identifierhttps://arxiv.org/abs/math/0504307
dc.identifierhttp://arxiv.org/abs/math/0504307
dc.identifierJ. Funct. Anal. 236 (2006), 351-368
dc.identifierdoi:10.1016/j.jfa.2006.02.001
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/101210
dc.subjectComplex Variables
dc.subjectFunctional Analysis
dc.subject30E10, 32E20, 46J10
dc.titlePolynomial approximation, local polynomial convexity, and degenerate CR singularities
dc.typetext

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