2023/03/14 by Hinkkanen, Aimo, Vuorinen, Matti
#30C80 #Complex Variables (math.CV) #FOS: Mathematics
paper · doi:10.48550/arxiv.2303.08238
We prove that if E is a compact subset of the unit disk \mathbb D in the complex plane, if E contains a sequence of distinct points an\not= 0 for n≥ 1 such that limn→∞ an=0 and for all n we have |an+1| ≥ (1)/(2) |an| , and if G=\mathbb D ∖ E is connected and 0∈ ∂ G, then there is a constant c>0 such that for all z∈ G we have λG (z) ≥ c/|z| where λG (z) is the density of the hyperbolic metric in G.