English

Bergman functions on weakly uniformly perfect domains II

Complex Variables 2026-07-16 v1

Abstract

We study the boundary asymptotic behavior of Bergman functions on planar domains. We prove that Ω\partial\Omega is uniformly perfect if and only if KΩ(1)(w)δΩ(w)4K_{\Omega}^{(1)}(w)\asymp \delta_{\Omega}(w)^{-4}. For weakly uniformly perfect boundaries, we establish lower and upper bounds for KΩ(1)K_{\Omega}^{(1)}, which characterize weak uniform perfectness. Combining these estimates with capacity upper bounds for the Bergman kernel, we derive optimal growth rates for the Bergman metric and Bergman distance on Zalcman-type domains; in particular, we obtain dΩloglogz1d_{\Omega}\gtrsim \log\log |z|^{-1} in the power-type case and dΩ(logz1)/(loglogz1)d_{\Omega}\gtrsim (\log |z|^{-1})/(\log\log |z|^{-1}) in the logarithmic-type case. Our results extend and refine earlier work of Chen and Xiong--Zheng.

Keywords

Cite

@article{arxiv.2607.14980,
  title  = {Bergman functions on weakly uniformly perfect domains II},
  author = {Zhiyuan Zheng},
  journal= {arXiv preprint arXiv:2607.14980},
  year   = {2026}
}