English

The Loewner Equation for Multiple Slits, Multiply Connected Domains and Branch Points

Complex Variables 2015-12-08 v2

Abstract

Let γ1,γ2:[0,T]D{0}\gamma_1,\gamma_2:[0,T]\to \overline{\mathbb{D}}\setminus\{0\} be parametrizations of two slits Γ1:=γ(0,T],Γ2=γ2(0,T]\Gamma_1:=\gamma(0,T], \Gamma_2=\gamma_2(0,T] such that Γ1\Gamma_1 and Γ2\Gamma_2 are disjoint. \\ Let gtg_t to be the unique normalized conformal mapping from D(γ1[0,t]γ2[0,t])\mathbb{D}\setminus (\gamma_1[0,t]\cup \gamma_2[0,t]) onto D\mathbb{D} with gt(0)=0,g_t(0)=0, gt(0)>0g'_t(0)>0. Furthermore, for k=1,2k=1,2, denote by hk;th_{k;t} the unique normalized conformal mapping from Dγk[0,t]\mathbb{D}\setminus \gamma_k[0,t] onto D\mathbb{D} with hk;t(0)=0,h_{k;t}(0)=0, hk;t(0)>0{h'_{k;t}(0)}>0.\\ Loewner's famous theorem (\cite{Loewner:1923}) can be stated in the following way: The function thk;tt\mapsto h_{k;t} is differentiable at t0t_0 if and only if tlog(hk;t(0))t\mapsto \log(h_{k;t}'(0)) is differentiable at t0t_0.\\ In this paper we compare the differentiability of thk;tt\mapsto h_{k;t} with that of tgt.t\mapsto g_t. We show that the situation is more complicated in the case t0=0t_0=0 with γ1(0)=γ2(0).\gamma_1(0)=\gamma_2(0).\\ Furthermore, we also look at this problem in the case of a multiply connected domain with its corresponding Komatu-Loewner equation.

Cite

@article{arxiv.1410.1825,
  title  = {The Loewner Equation for Multiple Slits, Multiply Connected Domains and Branch Points},
  author = {Christoph Böhm and Sebastian Schleißinger},
  journal= {arXiv preprint arXiv:1410.1825},
  year   = {2015}
}

Comments

24 pages, 10 figures

R2 v1 2026-06-22T06:15:18.984Z