Harmonic Function;
Riemann Surface;
Unit Circle;
Sharp Inequality;
Hyperbolic Distance;
D O I:
10.1007/BF02809900
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
We exhibit sharp inequalities comparing the hyperbolic distance land hy perbolic metric) to distances land associated metrics) defined via positive harmonic functions as well as bounded harmonic functions. In the simply connected case, all four inequalities are identities. For the non-simply connected case, we determine precisely when equality can hold: for a pair of points in a distance inequality, or a single point in a metric inequality.