English

Non-tangential limits for analytic Lipschitz functions

Complex Variables 2021-08-06 v1

Abstract

Let UU be a bounded open subset of the complex plane. Let 0<α<10<\alpha<1 and let Aα(U)A_{\alpha}(U) denote the space of functions that satisfy a Lipschitz condition with exponent α\alpha on the complex plane, are analytic on UU and are such that for each ϵ>0\epsilon >0, there exists δ>0\delta >0 such that for all zz, wUw \in U, f(z)f(w)ϵzwα|f(z)-f(w)| \leq \epsilon |z-w|^{\alpha} whenever zw<δ|z-w| < \delta. We show that if a boundary point x0x_0 for UU admits a bounded point derivation for Aα(U)A_{\alpha}(U) and UU has an interior cone at x0x_0 then one can evaluate the bounded point derivation by taking a limit of a difference quotient over a non-tangential ray to x0x_0. Notably our proofs are constructive in the sense that they make explicit use of the Cauchy integral formula.

Keywords

Cite

@article{arxiv.1811.11370,
  title  = {Non-tangential limits for analytic Lipschitz functions},
  author = {Stephen Deterding},
  journal= {arXiv preprint arXiv:1811.11370},
  year   = {2021}
}

Comments

9 pages, 1 figure, to appear in the Conference Proceedings of International Conference on Complex Analysis, Potential Theory, and Applications

R2 v1 2026-06-23T06:23:00.620Z