English

A note on a conjecture concerning boundary uniqueness

Complex Variables 2015-08-13 v2

Abstract

We consider the following conjecture (from Huang, et al): Let Δ+\Delta^+ denote the upper half disc in C\mathbb{C} and let γ=(1,1)\gamma = ( - 1, 1) (viewed as an interval in the real axis in C\mathbb{C}). Assume that FF is a holomorphic function on Δ+\Delta^+ with continuous extension up to γ\gamma such that FF maps γ\gamma into {\mboxImzC\mboxRez},\{|\mbox{Im} z|\leq C|\mbox{Re} z|\}, for some positive C.C. If FF vanishes to infinite order at 00 then FF vanishes identically. We show that given the conditions of the conjecture, either F0F\equiv 0 or there is a sequence in Δ+\Delta^+, converging to 0,0, along which \mboxImF/\mboxReF\mbox{Im} F/\mbox{Re} F (defined where \mboxReF0\mbox{Re} F\neq 0) is unbounded.

Keywords

Cite

@article{arxiv.1407.1763,
  title  = {A note on a conjecture concerning boundary uniqueness},
  author = {Abtin Daghighi and Steven G. Krantz},
  journal= {arXiv preprint arXiv:1407.1763},
  year   = {2015}
}
R2 v1 2026-06-22T04:57:11.158Z